docs: add contributing doc

Author: hperrin

CONTRIBUTING.md

@@ -0,0 +1,44 @@
+# Contributing
+
+Thank you for contributing! There are some guidelines you should know. First, let's get you started.
+
+## Setting up Your Dev Environment
+
+The first step is to fork the repo. Once you've got your own fork, check it out locally.
+
+```
+git clone git@github.com:yourusername/nymphjs.git nymphjs
+```
+
+Now let's get the repo set up for development.
+
+```
+cd nymphjs
+
+# This will take a while as it runs bootstrap.
+npm i
+```
+
+Now you're set up. If there are package-lock.json files updated after setting up, feel free to reset those changes.
+
+## Testing
+
+When you need to test something that involves one of the bigger DBs, there are DB run scripts called `test:db:run` that will set up a DB running in a docker container in the MySQL and Postgres driver directories. You can start all of them with the `test:db:run` script in the root dir.
+
+Once the DB container is running, you can run the `test` script.
+
+To stop the containers, don't use ctrl+C, instead run the `test:db:stop` script in another terminal window.
+
+### Test Tilmeld Setup App
+
+You can run `node packages/tilmeld-setup/test.mjs` to run a test Tilmeld Setup application available at [http://localhost:8080/user/](http://localhost:8080/user/).
+
+## Commiting Changes
+
+Nymph.js uses Prettier to format code. You should use Prettier after you've edited a file before you commit it. You can set up your editor to run Prettier automatically when you save a file. Also, don't forget the Svelte Prettier plugin.
+
+Nymph.js uses [conventional commits](https://www.conventionalcommits.org/en/v1.0.0/) for commit messages, and Husky will lint your commit messages when you commit. Please follow the conventional commits format for you commit messages. Please also provide meaningful, informative messages.
+
+Once you've made your change, feel free to open a pull request.
+
+Happy coding, and thanks again for contributing!