docs: add contributing guidelines (#679)

CONTRIBUTING.md

@@ -0,0 +1,60 @@
+# Contributing
+
+Thanks for being willing to contribute 🙌 If you contribute to this project, you agree to release your work under the license of this project.
+
+**Working on your first Pull Request?** You can learn how from this [First Contributions](https://github.com/firstcontributions/first-contributions)  guide.
+
+## Project setup
+
+1. Fork and clone the repo
+1. Run `yarn install` to install dependencies
+1. Create a branch for your PR with `git checkout -b pr/your-branch-name`
+
+> Tip: Keep your `master` branch pointing at the original repository and make
+> pull requests from branches on your fork. To do this, run:
+>
+> ```sh
+> git remote add upstream https://github.com/streamich/react-use.git
+> git fetch upstream
+> git branch --set-upstream-to=upstream/master master
+> ```
+>
+> This will add the original repository as a "remote" called "upstream," Then
+> fetch the git information from that remote, then set your local `master`
+> branch to use the upstream master branch whenever you run `git pull`. Then you
+> can make all of your pull request branches based on this `master` branch.
+> Whenever you want to update your version of `master`, do a regular `git pull`.
+
+## Development
+
+This library is a collection of React hooks so a proposal for a new hook will need to utilize the [React Hooks API](https://reactjs.org/docs/hooks-reference.html) internally to be taken into consideration.
+
+### Creating a new hook
+
+1. Create `src/useYourHookName.ts` and `src/__stories__/useYourHookName.story.tsx`, run `yarn start` to start the storybook development server and start coding your hook
+1. Create `src/__tests__/useYourHookName.test.ts`, run `yarn test:watch` to start the test runner in watch mode and start writing tests for your hook
+1. Create `src/docs/useYourHookName.md` and create documentation for your hook
+1. Export your hook from `src/index.ts` and add your hook to `README.md`
+
+You can also write your tests first if you prefer [test-driven development](https://en.wikipedia.org/wiki/Test-driven_development).
+
+### Updating an existing hook
+
+1. Run `yarn start` to start the storybook development server and start applying changes
+2. Update tests according to your changes using `yarn test:watch`
+3. Update documentation according to your changes
+
+## Committing and Pushing changes
+
+### Commit messages
+
+This repo uses [Angular-style semantic commits](https://github.com/angular/angular/blob/master/CONTRIBUTING.md#type) so prefix your commits with `fix:` or `feat:` if you want your changes to appear in [release notes](https://github.com/streamich/react-use/blob/master/CHANGELOG.md).
+
+### Git hooks
+
+There are git hooks set up with this project that are automatically enabled
+when you install dependencies. These hooks automatically test and validate your code when creating commits. They're really handy but can be temporarily disabled by adding a `--no-verify` flag to your commit command. This is useful when you want to commit and push some uncompleted code.
+
+## Help needed
+
+Please have a look at the [open issues](https://github.com/streamich/react-use/issues) and respond to questions, bug reports and feature requests. Thanks!