Upgrade Website to 0.80

[anupriya13]

Refer this https://github.com/microsoft/react-native-windows-samples/blob/main/website/README.md and this PR for 0.79: https://github.com/microsoft/react-native-windows-samples/pull/1042/files

Do similar changes for 0.80.
The commands for that would be:

Cutting Documentation for a New React Native Windows Release

1. Update necessary version references in docs.

   1. getting-started.md - make sure to update from "nightly" to "latest" and change the previous stable version from "latest" to "0.XX-stable" in react-native init.

2. Follow the Integration into the react-native-windows-samples-repo steps to add the latest API documentation.

3. If win10-compat.md has changed since the last version cut, copy contents of docs/win10-compat.md:

   1. The oldest version of win10-compat.md in versioned_docs should be replaced with the one from docs. Make sure to adjust the page id to match the older version.
   2. Confirm all other old versions of win10-compat.md should be deleted.

4. Snapshot the website for version 0.XX:

   1. cd website
   2. yarn run version 0.XX
   3. yarn run fix-unbroken

   This will create a new directory of versioned docs, version-0.XX, in website/versioned_docs. This will preserve all documents currently in the docs directory and make them available as documentation for version 0.XX. For more information on versioning, click here.

5. Edit website/.unbroken_exclusions and add the line !versioned_docs/version-0.XX/native-api/*-api-windows*.md underneath the other versioned doc exclusions listed at the top of the file.

6. Update support.js and add/update the entry for the new version of React Native Windows with the correct release and Active Support Start Date X (ex: 6/27/22). Then make sure to edit the previous version's:

   1. Maintenance Start Date (set to the last day of the month that's 1 month out from X, ex: 7/31/22)
   2. End of Support Date (set to the last day of the month that's 2 months out from X, ex: 9/30/22)

7. When you are ready for your new docs to be the default documentation on the website, edit website/siteConfig.js to point to 0.XX for its defaultVersionShown constant.

Once all changes are done, run " npx markdown-spellcheck "website/versioned_docs//*.md" "!website/versioned_docs//-api-windows.md" --en-us --ignore-acronyms --ignore-numbers --report --color
"

and add all the spelling errors to .spelling file