Touch up README.md and run clang-format via precommit hooks

[MatthewDaggitt]

This touches up the docs and adds instructions to them on how to get clang-format installed as a pre-commit hook in a slightly more robust way. In particular, we use pre-commit to ensure there's no need for a special bash script any more, and to make it easy for everyone to ensure that formatting runs whenever they commit.

@wu-haoze if you run then everything will be setup for you.

pip install pre-commit
pre-commit install

[wu-haoze]

@MatthewDaggitt Thanks for making this change! I suggest we keep the bash script as a low commitment option for one-time developers.

[MatthewDaggitt]

I suggest we keep the bash script as a low commitment option for one-time developers.

The problem is the bash script doesn't actually work for me.... In particular the shell I use doesn't calculate the path correctly with SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )".

I would argue that running the following once:

pip install pre-commit
pre-commit install

is less of a burden for one-time developers than running

apt install clang-format

and then much later, separately and repeatedly remembering to run

./tools/clang-format

(if the latter even works for them).

In particular I'm not sure we should be targeting "one-time" developers. We should be encouraging people to be at least "two-time" or "three-time" developers at least 😉

Having said that, if you would like to keep the bash script around then we can?