On NixOS, `bash` isn't under `/bin/bash` but rather in some directory in `$PATH`. Locally, I've been patching those scripts to make them work.

`/usr/bin/env` seems to be the only [portable way](https://unix.stackexchange.com/questions/29608/why-is-it-better-to-use-usr-bin-env-name-instead-of-path-to-name-as-my

) to use binaries from the PATH as interpreters.

Signed-off-by: Quentin Gliech <quentingliech@gmail.com>

I noticed that I'd occasionally have `scripts-dev/lint.sh` fail when messing about with config options in my PR. The script calls `scripts-dev/config-lint.sh`, which attempts some validation on the sample config.

 It does this by using `sed` to edit the sample_config, and then seeing if the file changed using `git diff`.

The problem is: if you changed the sample_config as part of your commit, this script will error regardless.

This PR attempts to change the check so that existing, unstaged changes to the sample_config will not cause the script to report an invalid file.

Add a linting script that enforces all boolean values in the default config be lowercase.

This has annoyed me for a while so I decided to fix it.