docs: centralize community files under .github and update README links

Author: dbongo

CODE_OF_CONDUCT.md renamed to .github/CODE_OF_CONDUCT.md

@@ -0,0 +1,9 @@
+# Contributing
+
+Here's how to get started:
+
+1. Fork the repo, then `git clone` your fork.
+2. Create a feature branch: `git checkout -b feat/my-feature`.
+3. Run tests: `bundle exec rspec`.
+4. Make your changes, commit, and push up your branch.
+5. Open a Pull Request describing your change.

.github/CONTRIBUTING.md

@@ -0,0 +1,25 @@
+<!-- PR Template -->
+
+## Summary
+A brief, one-sentence description of what this PR does.
+Link any related issues, e.g. `Closes #123`.
+
+## Motivation
+Why is this change needed? What problem does it solve?
+
+## Changes
+- High-level bullet points of the main changes.
+- New or modified classes/methods.
+- Any backward-incompatible changes.
+
+## Types of Changes
+- [ ] Bug fix
+- [ ] New feature
+- [ ] Breaking change
+- [ ] Documentation update
+
+## Checklist
+- [ ] I’ve added or updated tests and they pass (`bundle exec rspec`)
+- [ ] I’ve updated the README or relevant docs
+- [ ] I’ve bumped the version if this is a user-visible change
+- [ ] CI is green

.github/PULL_REQUEST_TEMPLATE.md

@@ -123,7 +123,13 @@ After cloning the repo, install dependencies with `bundle install`, then run tes
 
 ## Contributing
 
-Bug reports and pull requests are welcome on GitHub at https://github.com/dbongo/callable-mixin.
+Please follow these resources before submitting code or issues:
+
+- [Code of Conduct](https://github.com/dbongo/callable-mixin/blob/main/.github/CODE_OF_CONDUCT.md)
+- [Contributing Guide](https://github.com/dbongo/callable-mixin/blob/main/.github/CONTRIBUTING.md)
+- [Pull Request Template](https://github.com/dbongo/callable-mixin/blob/main/.github/PULL_REQUEST_TEMPLATE.md)
+
+Bug reports and pull requests are welcome on GitHub: https://github.com/dbongo/callable-mixin
 
 ## License