docs: add CONTRIBUTING.md with quality guidelines

Includes maturity level definitions (Production/Beta/Experimental),
entry format specification, and expanded acceptance criteria.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 0xarkstar

CONTRIBUTING.md

@@ -0,0 +1,48 @@
+# Contributing to Awesome Hermes Agent
+
+Thank you for helping make this list better. Please read these guidelines before opening a pull request.
+
+## Quality Bar
+
+Every entry MUST meet ALL of the following criteria:
+
+1. **Relevant** — Directly related to Hermes Agent, Hermes models, or the agentskills.io ecosystem.
+2. **Working** — Link returns 200 OK at time of submission.
+3. **Maintained** — Active within the last 12 months, or a stable reference like a paper.
+4. **Valuable** — Adds genuine value beyond what is in official documentation.
+5. **Described** — Concise, accurate description ending with a period.
+6. **Maturity level** — Includes a maturity indicator in the description.
+
+## Maturity Levels
+
+| Level | Criteria |
+|---|---|
+| `Production` | Tagged releases, documented API, active maintenance within last 6 months. |
+| `Beta` | Has README, installable, commits within last 3 months. |
+| `Experimental` | Repository exists with code, any activity within last 12 months. |
+
+## Entry Format
+
+```
+- [Name](https://url) - Description ending with period. `Production`
+```
+
+## How to Contribute
+
+1. Fork this repository.
+2. Add your entry in alphabetical order within the correct category.
+3. Run `npx awesome-lint` locally to verify formatting.
+4. Submit a pull request with:
+   - Clear title: "Add [Resource Name]"
+   - 1-2 sentences explaining why this resource is awesome.
+
+A maintainer will review within 7 days and may request changes. All submissions are checked for awesome-lint compliance before merging.
+
+## What We Do Not Accept
+
+- Self-promotional links without genuine community value.
+- Unmaintained or archived projects (no activity in 12+ months).
+- Duplicate entries or near-duplicates.
+- Entries that only repackage official documentation.
+- Bulk imports from other curated lists.
+- Purely commercial products without a free tier or open-source component.