Add shellcheck pre-commit hook

Summary:
pre-commit is a framework for managing Git pre-commit hooks.

Add a hook to run shellcheck, static analyzer for shell scritps.

Ref T1715.

Test Plan: Tested with rOPS repository

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1715

Differential Revision: https://devcentral.nasqueron.org/D2631