Refactor code structure for improved readability and maintainability

Formatting and Namespace Clean-up

Remove reference to altcha branch (everything is now on main).

Ammend credits and updates docs

Change default to built-in rate limiter instead of Redis.

Fix tabs formatting

Add Rate Limiting

Change name of challenge generator to be more specific

Mitigate replay vulnerability by using new expires option in Altcha

Add note about changing HMAC key

Merge branch 'altcha' into main

Add documentation for Altcha branch

Add Altcha implementation for Register and ForgotPasswqord Pages

Dark Mode fixes

Improved mobile view, improved screenshots in docs, removed double license file.