Update the tutorial for lesson 04 on interfaces. Also added images required for the base app. Created the placeholder for the next lesson so the app works if built from this branch. Updated navigation to include this step in the navigation menu.
PR Close#49980
Updates the learning content, the snippet regions from the code examples, and adds screenshots for the lesson. Also, add a base page for lesson-03
PR Close#49980
Update the content to complete the instructions required for users to build the app as described in lesson one. Also, added a new image that represents that app as of completing lesson-01.
PR Close#49980
Add application screenshot (and create the directory to host images for this tutorial). Also, update index.md instructions and complete TODOs/missing content.
PR Close#49980
Mark Thompson