Proposal: Tech Interview Handbook versioning

[xuanswe]

Let's say I read TIH a year ago and want to read it again now.
It would be nice to compare the current version (ex. 1.2 or 2022.XX) and the version I read last year (ex. 1.0 or 2023.YY).
It would be nice to compare somehow directly from the webpage https://www.techinterviewhandbook.org instead of using GitHub comparison. But the first step could be just using GitHub tags.