docs: update CONTRIBUTING.md (#199)

Author: andreshernandez-e2x

plugin/docs/CONTRIBUTING.md

@@ -13,14 +13,32 @@ our team in determining a solution for the issue.
 
 ## Raising a Pull Request
 
-After your changes are ready for review, raise a PR with your branch against master!
+After your changes are ready for review, raise a PR with your branch against `main`!
 
 > ℹ️ If you are releasing a patch for a version, please branch off
 > of the appropriate stable release branch or tag. When your PR is ready for review,
 > raise the PR against the stable release branch. If one doesn't exist, ask the
 > maintainers to create one.
 
+Our current way of working with PRs involves committing and reviewing changes internally
+in a private repository and then syncing said changes to the public repository (with
+a mention the the original author of course).
+
+To speed up the process (or just notify us in case we may have missed it) send us an email at
+thirdpartysupport@klaviyo.com, we'll make sure to take a look.
+
 ## Local Environment
 
 Check the [plugin development and customization documentation](./plugin-development-customization.md) for all the
 details on how to install and test the plugin on your local environment.
+
+## Code recommendations
+
+Ideally, code contributions should:
+
+- Use descriptive names for variables and functions, to communicate intent.
+- Use `prettier` and `yarn run lint` (or `yarn run lint:fix`) to help
+your code look clean and organized.
+- Have _some_ test coverage, if appropriate. We try to stay above 80% coverage.
+- If considerably changing or introducing some behavior/feature, optionally add
+some documentation (or provide a summary in your PR, so we can write some instead).