feat: wrote contribution guidelines

CONTRIBUTING.md

@@ -0,0 +1,17 @@
+# Contributing
+
+Harper is completely open to outside contributors of any kind.
+
+If you have a feature request or bug to report, please [create an issue](https://github.com/elijah-potter/harper/issues).
+
+## Committing
+
+Harper follows [conventional commit practices](https://www.conventionalcommits.org/en/v1.0.0/). 
+Before creating a pull request, please make sure all your commits follow the linked conventions.
+
+Additionally, to minimize the labor required to review your commit, we run a relatively strict suite of formatting and linting programs.
+We highly recommend that you run both `format.sh` and `precommit.sh` before submitting a pull request.
+If those scripts don't work in your environment, we run `precommit.sh` through GitHub actions inside of pull requests, so you may make modifications and push until the checks pass.
+
+If this sounds intimidating, don't worry.
+We are entirely willing to work with you to make sure your code can make it into Harper, just know it might take a little longer.

README.md

@@ -35,3 +35,6 @@ If you want to use Harper on your machine, you will want to look at the [documen
 
 We consider long lint times bugs.
 If you encounter any significant performance issues, please create an issue on the topic.
+
+If you find a fix to any performance issue, we are open the contribution.
+Just make sure to read [our contribution guidelines first.](https://github.com/elijah-potter/harper/blob/master/CONTRIBUTING.md)