bootloader: Remove redudant date information

[timg236]

Drop explicit references to pre-2021 bootloader releases because
there's been two default releases since then. The older releases
aren't supported because they won't work on all Pi variants.

[timg236]

@peterharperuk @lurch

[peterharperuk]

I approve :)

[aallan]

@timg236 I rebased the PR from master to develop as the default branch for the repo is now develop. Commits to master auto-build and deploy the actual documentation site. For future PRs can you make sure you're against the develop branch? Thanks!

[timg236]

@timg236 I rebased the PR from master to develop as the default branch for the repo is now develop. Commits to master auto-build and deploy the actual documentation site. For future PRs can you make sure you're against the develop branch? Thanks!

Will do. Sorry, wasn't aware of the branch structure, I did get a bit confused by the bot error !

[aallan]

Will do. Sorry, wasn't aware of the branch structure, I did get a bit confused by the bot error !

No worries! Something we added when we moved from Markdown to Asciidoc.

The default branch of the repo is develop and we all work there. PRs to develop need an approval from someone (I actually can't remember the whole list of folks) to commit it on to the branch.

You can only commit to master from the develop branch and not some other random branch, and commits to master can only be done by me or another repo admin, but will trigger and auto-deploy of the site.

That means any PR has to be reviewed, and should spend some time on develop on people's local machines before going to the production site, and there's now two steps between a PR getting committed and it breaking the site somehow.

Arguably we should have had a production branch, which was the branch that auto-deploys rather than using master, as it's a little bit non-standard, but seems to be working pretty well.