Update overall plugin description

[annezazu]

Description

This is an update to the overall plugin description to do the following:

• Ensure the content is up to date (correct phases, links to 2020 items, adjust descriptions in light of FSE etc).
• Add in more context and helpful hints around when you need to use the plugin to better direct folks.
• Add in extra links to make it easier to get involved with contributing and staying up to date.
• Clean up the language to make it a bit simpler.

If anyone has any suggestions for links to add under "where can I learn more", please share!

How has this been tested?

Screenshots

Types of changes

Enhancement

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR (please manually search all *.native.js files for terms that need renaming or removal).

[annezazu]

Thanks so much for reviewing and adding in suggestions @aristath !