Add instructions on pre-commit setup

[obulat]

Problem

Recently, when setting up the local dev environment with @firatbezir, we found that the setup guide does not mention pre-commit. And without setting up pre-commit, contributors cannot commit or push anything (without the --no-verify flag).

Description

Add the instructions for setting up pre-commit to the general setup documentation.

@dhruvkb, what is the best way of setting it up? Running just precommit?

Alternatives

Additional context

[dhruvkb]

Yes @obulat, just precommit should download the .pyz package and install the Git hooks. Some of our hooks require Docker and will fail unless they find it so in a way that's a prerequisite to this or we're back to --no-verify.

And without setting up pre-commit, contributors cannot commit or push anything

This cannot be right. Unless you set up the hooks (which just precommit does), git should allow you to commit and push anything.

[dhruvkb]

This is a fresh clone without just precommit. One is free to commit any change when the hooks have not been installed, see no checks ran for step 4.