zeppelin/docs/displaysystem
AhyoungRyu 641a641c31 [HOT FIX] Fix broken display_formula.png by using relative path
### What is this PR for?
Currently `display_formula.png` (added by #1606) is broken in here: http://zeppelin.apache.org/docs/0.7.0-SNAPSHOT/displaysystem/basicdisplaysystem.html#mathematical-expressions

Fixed it by using relative path for the image. But have no idea why the other image files are not broken in that page.

### What type of PR is it?
Documentation | Hot Fix

### Todos
* [ ] - Task

### What is the Jira issue?
N/A

### How should this be tested?
It can't be reproduced using docs dev mode. Needs to be tested with below steps.

```
1) build gh-pages (website) branch
JEKYLL_ENV=production bundle exec jekyll build
cp -r _site/ /tmp/zeppelin_website/
mkdir -p /tmp/zeppelin_website/docs/0.7.0-SNAPSHOT

2) build this patch (docs) and copy it under docs/0.7.0-SNAPSHOT of website
cd docs
bundle exec jekyll build --safe
cp -r _site/ /tmp/zeppelin_website/0.7.0-SNAPSHOT/

3) start httpserver and browse http://localhost:8000/docs/0.7.0-SNAPSHOT/
cd /tmp/zeppelin_website
python -m SimpleHTTPServer
```

### Screenshots (if appropriate)
**Before**
 - In the official website
<img width="938" alt="screen shot 2016-12-13 at 7 07 27 pm" src="https://cloud.githubusercontent.com/assets/10060731/21136061/72c230b6-c167-11e6-9805-12d6f11f3270.png">

```
GET http://zeppelin.apache.org/assets/themes/zeppelin/img/screenshots/display_formula.png 404 (Not Found)
```

**After**
 - test locally using same with production path
<img width="877" alt="screen shot 2016-12-13 at 7 09 42 pm" src="https://cloud.githubusercontent.com/assets/10060731/21136136/bbff660e-c167-11e6-9ed3-384e609886fe.png">

### Questions:
* Does the licenses files need update?
* Is there breaking changes for older versions?
* Does this needs documentation?

Author: AhyoungRyu <fbdkdud93@hanmail.net>

Closes #1752 from AhyoungRyu/fix-img-path and squashes the following commits:

4be330b [AhyoungRyu] Fix broken display_formula.png by using relative path
2016-12-13 16:03:29 -08:00
..
back-end-angular.md [ZEPPELIN-1219] Add searching feature to Zeppelin docs site 2016-08-10 12:39:22 +09:00
basicdisplaysystem.md [HOT FIX] Fix broken display_formula.png by using relative path 2016-12-13 16:03:29 -08:00
front-end-angular.md [ZEPPELIN-1665] Z.run with external note executable and access resource for zeppelin in each interpreter 2016-11-29 08:07:15 -08:00