PE-410: Redesigned README as simple landing page

[jdmedlin1]

📝 Description

The current root README should be split into multiple READMEs for easier digestion of information. My thought is the root README should include simple info like intro to BrightSign, project structure, where to begin, where to go to hit the ground running, and then explanation of repo maintenance and interaction.

Auxiliary READMEs should exist for an “examples” and “templates” directories to help teach and navigate respectively. These will be created once the PE-411 effort has been merged.

Issue: Url to Github Issue

📋 List of Changes

• Please provide a concise list of the main changes.

🧪 Steps to Test

1. Step 1

Notes to the Reviewer

📸 Screenshots

✔️ Dev Complete Checklist

• [ ] PR template filled out
• [ ] Change is tested by submitter
• [ ] PR follows all linting and coding standards
• [ ] Github Issue exists (if applicable)
• [ ] Team member has been assigned
• [ ] At least one commit message is in Conventional Commit format