Next release/version simple

[jacoblogan]

Description of changes:

Here is the simplified version switcher

• Build a backend is the only versioned content
• any page not in the build a backend section will land the user on the current version
• Switching your version from any page will take you to the corresponding page on the previous version or to build a backend if there is no corresponding page

Staging Site: https://next-release-version-simple.dmhjrabi3pkql.amplifyapp.com/

Related GitHub issue #, if available:

Instructions

If this PR should not be merged upon approval for any reason, please submit as a DRAFT

Which product(s) are affected by this PR (if applicable)?

• amplify-cli
• amplify-ui
• amplify-studio
• amplify-hosting
• amplify-libraries

Which platform(s) are affected by this PR (if applicable)?

• JS
• iOS
• Android
• Flutter
• React Native

Please add the product(s)/platform(s) affected to the PR title

Checks

• Does this PR conform to the styleguide?

• Does this PR include filetypes other than markdown or images? Please add or update unit tests accordingly.

• Are any files being deleted with this PR? If so, have the needed redirects been created?

• Are all links in MDX files using the MDX link syntax rather than HTML link syntax?
  
  ref: MDX: [link](https://link.com)
  HTML: <a href="https://link.com">link</a>

When this PR is ready to merge, please check the box below

• Ready to merge

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[hbuchel]

I clicked all over the place locally and on the staging site and LGTM!