Making release notes searchable in our docs

[nsjames]

AC:

• During build time create a directory for release notes so that they can be searchable
  • Get GITHUB_TOKEN we can use for APIs (https://docs.github.com/en/rest/releases/releases?apiVersion=2022-11-28#list-releases)
  • Pull release notes during build time for CDT, Leap, DUNE, EOS System contracts
  • Cache release notes with the last update time, so we can cache-bust later
  • Create a directory hierarchy with versions