add dco (#169)

Signed-off-by: Daniel Guns <danbguns@gmail.com>

Author: dgunzy

.github/workflows/ci.yml

@@ -9,10 +9,6 @@ on:
       - "CHANGELOG.md"
   pull_request:
     branches: [main]
-    paths-ignore:
-      - "**.md"
-      - "docs/**"
-      - "CHANGELOG.md"
 
 permissions:
   contents: read

CONTRIBUTING.md

@@ -0,0 +1,34 @@
+# Contributing to flux9s
+
+Thank you for your interest in contributing!
+
+## DCO Sign-off
+
+All commits must be signed off with the [Developer Certificate of Origin (DCO)](https://developercertificate.org/). Add `-s` to your commit command:
+
+```sh
+git commit -s -m "your commit message"
+```
+
+This adds a `Signed-off-by` trailer to the commit. The DCO check will fail on PRs without it.
+
+## Development
+
+See the [Developer Guide](DEVELOPER_GUIDE.md) for setup and architecture details.
+
+**Before submitting a PR, run:**
+
+```sh
+just ci
+```
+
+This runs formatting, linting, and tests — the same checks CI runs.
+
+## Submitting a Pull Request
+
+1. Fork the repo and create a branch from `main`
+2. Make your changes with signed-off commits
+3. Ensure `just ci` passes locally
+4. Open a PR targeting `main`
+
+PRs require one approving review and all CI checks to pass before merging.