Add a pre-commit config

[gregcorbett]

Similar to the config for APEL's SSM: https://github.com/apel/ssm/blob/dev/.pre-commit-config.yaml, GOCDB should at least have the following checks

  # Other checks
  - id: check-added-large-files
  - id: check-merge-conflict
  - id: check-yaml
  - id: debug-statements
  - id: end-of-file-fixer
  - id: mixed-line-ending
    name: Force line endings to LF
    args: ['--fix=lf']
  - id: trailing-whitespace

It would be useful to look if there are PHP specific checks we can use and if so, potentially included them.