Add hints for merge tools + mention pull

[phil-blain]

First, great page. Clear, to the point, and visually appealing.

When using git mergetool, the signification of LOCAL and REMOTE is also reversed when doing git rebase vs git merge. I think it could be valuable to also mention that on your page, with some examples. Would you be willing to accept a PR ?

Also, maybe mention that the behavior is the same when issuing git pull vs git pull --rebase (might not be obvious for newbies.)

[Nitaym]

Thanks! Did you open a PR? I don't see any

[phil-blain]

I did not yet! I just wanted to check with you if you would think this is useful :)