Make historical documentation available

Continuing the discussion from Firewall-Settings for Syncthing?:

I am not sure of the build process for the documentation but I would like to be able to link to versions of the docs that have previous configuration options (similar to what dovecot does, Alternatively perhaps a method to select the version you are running for any parameters that change between releases.

What I usually do is check out the Git history for a given document if I need to go back in time:

The problem is the protocol changes etc. aren’t necessarily highlighted so you might not know you need to find the outdated documentation.

This is a fair ask, you should open a ticket in the docs repo. Yet all the docs are shipped with each release.

For reference: