Secure Store and React Redux for Persistent Sign-in (and user information)

[ehng359]

Implemented fully functional flows for sign-in and sign-out with user persistence across both and updated documentation on the WriteGirl Notion.

Features

• Closing the application and re-opening the app correctly redirects us to the home page (with the correct user logged in).
• Logging out and re-opening the application correctly keeps us logged out
• Sign-in flow altered to automatically log into the application after signing up.
• Added intermediary loading screen to provide application time to figure out signed in or signed out...

Demonstrated features:
https://github.com/lablueprint/write-girl/assets/94334288/b0398970-1446-4f7d-8848-ebb304c13660

[ehng359]

Still need to merge with main