Create CONTRIBUTING.md

CONTRIBUTING.md

@@ -0,0 +1,33 @@
+All contributions are welcome – especially:
+
+- documentation,
+- bug reports and issues,
+- code contributions.
+
+### Code
+
+If you'd like to actively develop or help maintain this project then there are existing tests against which you can test the library with. Typically, this looks like
+
+- `git clone git@github.com:aliev/aioauth.git`
+- `cd aioauth`
+- `python -mvenv env`
+- `source env/bin/activate`
+- `make dev-install`
+
+`make dev-install` will also install all the required packages that will allow you to adhere to the code styling guide of `aioauth`.
+
+Basically we use the `black` and `flake8` packages for code formatting, `pre-commit` package will check the code formatting before your first commit is made.
+
+To automatically correct the formatting you can run the command inside the repository root:
+
+```
+pre-commit run --all-files
+```
+
+Running tests:
+
+```
+make test
+```
+
+the output result will also show the current coverage, please make sure the coverage is not below `99%`