[GIT] Add example for pushinsteadof

Thanks to:
https://speakerdeck.com/uasi/git-raihuwokuai-shi-nisuruzhi-rarezarukomandotati
[GIT] set autosquash to true for rebase

Thanks to:
https://speakerdeck.com/uasi/git-raihuwokuai-shi-nisuruzhi-rarezarukomandotati