Introduce pre-commit hooks (#83)

.pre-commit-config.yaml

@@ -0,0 +1,18 @@
+repos:
+-   repo: local
+    hooks:
+    - id: black
+      name: black
+      language: system
+      entry: black
+      types: [python]
+    - id: isort
+      name: isort
+      language: system
+      entry: isort -y
+      types: [python]
+    - id: flake8
+      name: flake8
+      language: system
+      entry: flake8
+      types: [python]

README.md

@@ -23,13 +23,24 @@ make start
 
 And access GraphiQL at [http://localhost:8000/graphql](http://localhost:8000/graphql)
 
-## Testing
+## Development
+
+### Testing
 Run tests by executing:
 
 ```bash
 make install-dev
 make test
 ```
 
+### Setup pre commit
+
+Pre commit hooks is an additional option instead of excuting checks in your editor of choice.
+
+```bash
+pip install pre-commit
+pre-commit install
+```
+
 ## License
 Code released under the [MIT license](LICENSE).