Adds the content for lesson 07, a new image, a navigation entry and some updates to the example code for this lesson. Also, this updates previous lessons where typos and copy/pasta errors show up
PR Close#49980
Each individual lesson should have the images available in the download since a learner can start from any lesson. So, we're adding images here. Also, sync'ing styles for consistency across the lessons. This is fixing some previous commits that didn't include these changes. The goal is that for future commits we can have less changes and focused solely on that lesson
PR Close#49980
The commit enables the @typescript-eslint/quotes rule which mendates single quotes over doubles and allows template literals with backticks.
PR Close#48952
