Makes the project more friendly to GitHub users by providing
conventional files.
Those changes will improve our score under the GitHub
community tab:
https://github.com/Respect/Validation/community
- The CHANGELOG.md file was removed. It was outdated and
not being maintained.
- Minimalistic .github/PULL_REQUEST_TEMPLATE.md
- Minimalistic .github/SECURITY.md
- Minimalistic .github/CODE_OF_CONDUCT.md
- Minimalistic .github/ISSUE_TEMPLATE
