Merge pull request #6816 from ethereum-optimism/refcell/labels-spec

feat: Contributing label definitions

CONTRIBUTING.md

@@ -185,3 +185,37 @@ cd packages/contracts
 pip3 install slither-analyzer
 pnpm test:slither
 ```
+
+## Labels
+
+Labels are divided into categories with their descriptions annotated as `<Category Name>: <description>`.
+
+The following are a comprehensive list of label categories.
+
+- **Area labels** ([`A-`][area]): Denote the general area for the related issue or PR changes.
+- **Category labels** ([`C-`][category]): Contextualize the type of issue or change.
+- **Meta labels** ([`M-`][meta]): These add context to the issues or prs themselves primarily relating to process.
+- **Difficulty labels** ([`D-`][difficulty]): Describe the associated implementation's difficulty level.
+- **Status labels** ([`S-`][status]): Specify the status of an issue or pr.
+
+Labels also provide a versatile filter for finding tickets that need help or are open for assignment.
+This makes them a great tool for contributors!
+
+[area]: https://github.com/ethereum-optimism/optimism/labels?q=a-
+[category]: https://github.com/ethereum-optimism/optimism/labels?q=c-
+[meta]: https://github.com/ethereum-optimism/optimism/labels?q=m-
+[difficulty]: https://github.com/ethereum-optimism/optimism/labels?q=d-
+[status]: https://github.com/ethereum-optimism/optimism/labels?q=s-
+
+#### Filtering for Work
+
+To find tickets available for external contribution, take a look at the [`M-community`][M-community] label.
+
+You can filter by the [`D-good-first-issue`][D-good-first-issue]
+label to find issues that are intended to be easy to implement or fix.
+
+Also, all labels can be seen by visiting the [labels page][labels]
+
+[labels]: https://github.com/ethereum-optimism/optimism/labels
+[M-community]: https://github.com/ethereum-optimism/optimism/labels/M-community
+[D-good-first-issue]: https://github.com/ethereum-optimism/optimism/labels/D-good-first-issue