Document Project authoring and Build process

[Nirmal4G]

With the following PRs re-organizing the MSBuild logic, it's time we add project authoring and the build process to the Wiki.

1. Update package titles and consolidate build logic WindowsCommunityToolkit#3894
2. Convert DesignTools projects to Sdk-style WindowsCommunityToolkit#3794

[ghost]

Hello Nirmal4G, thank you for opening an issue with us!

I have automatically added a "needs triage" label to help get things started. Our team will analyze and investigate the issue, and escalate it to the relevant team if possible. Other community members may also look into the issue and provide feedback 🙌

[Nirmal4G]

Documenting CI process is tracked in #2
Documenting DesignTools projects is tracked in #3