fix: URLs in development

docs/development/contribution/how_to_contribute_code.md

@@ -2,7 +2,7 @@
 layout: page
 title: "Contributing to Apache Zeppelin (Code)"
 description: "How can you contribute to Apache Zeppelin project? This document covers from setting up your develop environment to making a pull request on Github."
-group: development
+group: development/contribution
 ---
 <!--
 Licensed under the Apache License, Version 2.0 (the "License");

docs/development/contribution/how_to_contribute_website.md

@@ -2,7 +2,7 @@
 layout: page
 title: "Contributing to Apache Zeppelin (Website)"
 description: "How can you contribute to Apache Zeppelin project website? This document covers from building Zeppelin documentation site to making a pull request on Github."
-group: development
+group: development/contribution
 ---
 <!--
 Licensed under the Apache License, Version 2.0 (the "License");

docs/development/helium/overview.md

@@ -0,0 +1,27 @@
+---
+layout: page
+title: "Helium"
+description: ""
+group: development/helium
+---
+<!--
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+{% include JB/setup %}
+
+# Helium Overview
+
+<div id="toc"></div>
+
+## What is Helium? 
+

docs/development/helium/writing_application.md

@@ -1,8 +1,8 @@
 ---
 layout: page
-title: "Writing a new Application"
+title: "Writing a new Helium Application"
 description: "Apache Zeppelin Application is a package that runs on Interpreter process and displays it's output inside of the notebook. Make your own Application in Apache Zeppelin is quite easy."
-group: development
+group: development/helium
 ---
 <!--
 Licensed under the Apache License, Version 2.0 (the "License");

docs/development/helium/writing_spell.md

@@ -1,8 +1,8 @@
 ---
 layout: page
-title: "Writing a new Spell"
+title: "Writing a new Helium Spell"
 description: "Spell is a kind of interpreter that runs on browser not on backend. So, technically it's the frontend interpreter. "
-group: development
+group: development/helium
 ---
 <!--
 Licensed under the Apache License, Version 2.0 (the "License");
@@ -34,7 +34,7 @@ It can provide many benefits.
 
 ## How it works
 
-Helium Spell works like [Helium Visualization](./writingzeppelinvisualization.html).
+Helium Spell works like [Helium Visualization](./writing_visualization_basic.html).
 
 - Every helium packages are loaded from central (online) registry or local registry
 - You can see loaded packages in `/helium` page.
@@ -47,19 +47,19 @@ Helium Spell works like [Helium Visualization](./writingzeppelinvisualization.ht
 
 Find a spell what you want to use in `/helium` package and click `Enable` button.
 
-<img class="img-responsive" style="width:70%" src="../assets/themes/zeppelin/img/docs-img/writing_spell_registered.png" />
+<img class="img-responsive" style="width:70%" src="/assets/themes/zeppelin/img/docs-img/writing_spell_registered.png" />
 
 ### 2. Using
 
 Spell works like an interpreter. Use the `MAGIC` value to execute spell in a note. (you might need to refresh after enabling)
 For example, Use `%echo` for the Echo Spell.
 
-<img class="img-responsive" style="width:70%" src="../assets/themes/zeppelin/img/docs-img/writing_spell_using.gif" />
+<img class="img-responsive" style="width:70%" src="/assets/themes/zeppelin/img/docs-img/writing_spell_using.gif" />
 
 
 ## Write a new Spell
 
-Making a new spell is similar to [Helium Visualization#write-new-visualization](./writingzeppelinvisualization.html#write-new-visualization).
+Making a new spell is similar to [Helium Visualization#write-new-visualization](./writing_visualization_basic.html#write-new-visualization).
 
 - Add framework dependency called zeppelin-spell into `package.json`
 - Write code using framework
@@ -198,7 +198,7 @@ It's automatically created when you publish to npm repository but in local case,
 - Place this file in your local registry directory (default `$ZEPPELIN_HOME/helium`).
 - `type` should be `SPELL`
 - Make sure that `artifact` should be same as your spell directory.
-- You can get information about other fields in [Helium Visualization#3-create-helium-package-file-and-locally-deploy](./writingzeppelinvisualization.html#3-create-helium-package-file-and-locally-deploy).
+- You can get information about other fields in [Helium Visualization#3-create-helium-package-file-and-locally-deploy](./writing_visualization_basic.html#3-create-helium-package-file-and-locally-deploy).
 
 ### 4. Run in dev mode
 

docs/development/helium/writing_visualization_basic.md

@@ -1,8 +1,8 @@
 ---
 layout: page
-title: "Writing a new Visualization"
+title: "Writing a new Helium Visualization: basic"
 description: "Apache Zeppelin Visualization is a pluggable package that can be loaded/unloaded on runtime through Helium framework in Zeppelin. A Visualization is a javascript npm package and user can use them just like any other built-in visualization in a note."
-group: development
+group: development/helium
 ---
 <!--
 Licensed under the Apache License, Version 2.0 (the "License");
@@ -41,7 +41,7 @@ Once Zeppelin loads _Helium package files_ from registries, available packages a
 
 Click 'enable' button.
 
-<img class="img-responsive" style="width:70%" src="../assets/themes/zeppelin/img/docs-img/writing_visualization_helium_menu.png" />
+<img class="img-responsive" style="width:70%" src="/assets/themes/zeppelin/img/docs-img/writing_visualization_helium_menu.png" />
 
 
 #### 3. Create and load visualization bundle on the fly
@@ -53,7 +53,7 @@ Once a Visualization package is enabled, [HeliumBundleFactory](https://github.co
 Zeppelin shows additional button for loaded Visualizations.
 User can use just like any other built-in visualizations.
 
-<img class="img-responsive" style="width:70%" src="../assets/themes/zeppelin/img/docs-img/writing_visualization_example.png" />
+<img class="img-responsive" style="width:70%" src="/assets/themes/zeppelin/img/docs-img/writing_visualization_example.png" />
 
 
 
@@ -134,8 +134,10 @@ Place this file in your local registry directory (default `./helium`).
 
 ##### type
 
-When you're creating a visualization, 'type' should be 'VISUALIZATION'.
-Check [application](./writingzeppelinapplication.html) type if you're interested in the other types of package.
+When you're creating a visualization, 'type' should be 'VISUALIZATION'. Check these types as well.
+
+- [Helium Application](./writing_application.html)
+- [Helium Spell](./writing_spell.html)
 
 ##### name
 

docs/development/helium/writing_visualization_transformation.md

@@ -1,8 +1,8 @@
 ---
 layout: page
-title: "Transformations for Zeppelin Visualization"
+title: "Transformations in Zeppelin Visualization"
 description: "Description for Transformations"
-group: development
+group: development/helium
 ---
 <!--
 Licensed under the Apache License, Version 2.0 (the "License");

docs/index.md

@@ -37,7 +37,7 @@ limitations under the License.
   </div>
   <div class="col-sm-6 col-md-6" style="padding:0;">
     <div class="hidden-xs" style="margin-top: 60px;"></div>
-    <img class="img-responsive" style="border: 1px solid #ecf0f1;" src="./assets/themes/zeppelin/img/notebook.png" />
+    <img class="img-responsive" style="border: 1px solid #ecf0f1;" src="/assets/themes/zeppelin/img/notebook.png" />
   </div>
 </div>