Add installation of Git hooks.

[Alexhuszagh]

Add scripts to install or uninstall any Git hooks, currently used for pre-commit hooks. The generated precommit hook does linting, formatting, and tests the script can run basic tests.

#!/usr/bin/env bash
#
# A custom Git hook.

set -eux pipefail

hooks_home="$(dirname "$(realpath "${BASH_SOURCE[0]}")")"
git_home="$(dirname "${hooks_home}")"
project_home="$(dirname "${git_home}")"

scripts/lint.sh
scripts/fmt.sh
scripts/configure.sh