Tutorial: Add tutorial for creating a browser app

[FunctionPoint]

So a step-by-step for creating your own app.
Start with a copy of the Counter example.
Go through all the baseline config, but don't require the student to re-enter it.
Explain app startup through TS. (Explain why TS and not JS).
Rename classes, re-implement methods.
...
Add tests in testing framework in separate tutorial section.
Explain deployment.

Store the end result as a new project in Contributions.
What should the functionality of the app be?
Something simple but not too common.

[FunctionPoint]

App idea: Text Analyzer

User pastes text, clicks button, app shows:

• Word count by frequency
• Longest / shortest words

Demonstrates:

• Strings & arrays
• Maps / dictionaries
• Sorting
• HTML GUI binding
• Event handling (button press)