[chapter 1] Add link for git tips

[satsie]

Not sure the best place for this, but I wrote up some tips on how I've learned to use git in the context of Bitcoin Core. Jonas suggested possibly adding it to this repo. I'll let you decide if it belongs here or not :smile:

[willcl-ark]

Wow this is great, thanks @satsie!

As I was reading I kept thinking to myself: "but.... git reflog!" So was glad to see that get a shout in the end.

I enjoyed learning git log --oneline master.. as I have been piping to head git log --oneline | head -n <guess number> then counting, which seems really dumb in hindsight 😋

[willcl-ark]

Very happy to merge this as-is, but I'd kind of like to draw more attention to it due to how awsome and useful it is, and its current linkage feels a bit humble!

Well i'll go for it like this and perhaps expand it's description/draw more attention to it in a follow up :)