Add a inc/ file with a link to the release notes
_Originally created by @sajolida on [#7665 (Redmine)](https://public-redmine-archive.tails.boum.org/code/issues/7665)_ According to tails/tails#7650, we need to add a link to the latest release notes in the upgrade instructions. Let’s do this with the same trick that we do the ISO image URL, torrent URL, and SHA256 checksum, which is using a dedicated file in wiki/src/inc. Then we need to upgrade the release process documentation to have this updated by the release manager. Marking this as a task for 1.1.1, so that the RM doesn’t have to upgrade the content of bbbfd42 manually. This is an easy task but I’ll do it if nobody takes it over. Feature Branch: web/7665-add-inc-file-for-release-notes
issue