probot pull auto reset my branch

[atian25]

when I install this bot, it auto reset my master branch and make the existing PR to close and can't be restored.

it makes one of my PR will need to rerun unittest(which will build for 1 hour) and another 3 days to wait for merge.

I understand that this bot will force reset by default, but suggest to notify users at README.

nodejs/node#35096

[wei]

Hi @atian25, I make it pretty clear to make a backup both at time of app install and in README with a yellow ⚠️ sign. I also have the hard reset bold.

Pull app will automatically watch and pull in upstream's default (master) branch to yours with hard reset.

Do you have any suggestions in addition to what's already in place? 😃