add CONTRIBUTING

Author: keithamus

CONTRIBUTING.md

@@ -0,0 +1,26 @@
+# Contributing
+
+Contributions are always welcome! Before contributing, please read the [code of conduct](https://github.com/WebComponentsGuide/webcomponents.guide/blob/main/CODE_OF_CONDUCT.md).
+
+## Where to start
+
+- If you've found typos or mistakes in the documentation, please go right ahead and raise a PR!.
+- If you're looking for issues to resolve, a good place to start is the [help wanted label](https://github.com/WebComponentsGuide/webcomponents.guide/labels/help%20wanted) and/or [good first issue label](https://github.com/WebComponentsGuide/webcomponents.guide/labels/good%20first%20issue).
+- If you have to contribute to bigger pieces, like an idea or new section, tutorial, or blog post, then please raise an issue first! This way we can discuss an action plan and figure out a high level overview of what should be written. 
+
+### Setup
+
+You can run the code locally by cloning the repository, and running `npm install` followed by `npm start`:
+
+```sh
+$ git clone [email protected]:WebComponentsGuide/webcomponents.guide
+$ cd webcomponents.guide
+$ npm install
+$ npm start
+```
+
+Once this is done you can visit http://localhost:8080/ to see the local copy of the website. As you edit files the website will automatically rebuild, and you can see the changes reflected in your browser.
+
+### Running checks/tests
+
+When making contributions, please make sure to run `npm run check`, to ensure your contributions are correctly formatted and spelled. You can also run `npm run format` to automatically format all files.