docs: add contributor guidance and community reporting routes

Add contribution, conduct, security, and support guidance plus bug,
feature, and pull request templates. Set the project conduct contact
and use the canonical documentation domain.

Community drafts by the Planner agent; source, privacy, and final
preparation corrections by the Guard agent.

Co-authored-by: OpenRig agent (dev-planner) <[email protected]>

.github/SUPPORT.md

@@ -0,0 +1,16 @@
+# Getting help with OpenRig
+
+- **Docs:** https://openrig.dev/docs — getting started, CLI reference, configuration,
+  troubleshooting. An index linking to agent-friendly documentation is at
+  https://openrig.dev/llms.txt.
+- **Questions:** [Discussions › Q&A](https://github.com/mvschwarz/openrig/discussions/categories/q-a).
+- **Bugs:** [open an issue](https://github.com/mvschwarz/openrig/issues/new/choose) with the bug
+  template. Include `rig --version`, your OS and Node versions, and relevant redacted command output.
+  Reports are public: remove credentials, private prompts and personal information.
+- **Ideas and setups:** [Ideas](https://github.com/mvschwarz/openrig/discussions/categories/ideas)
+  and [Show and tell](https://github.com/mvschwarz/openrig/discussions/categories/show-and-tell).
+- **Videos:** https://www.youtube.com/@openrig
+- **Security:** see [SECURITY.md](../SECURITY.md); please report privately.
+
+We aim to acknowledge issues and pull requests within one day. A substantive PR review decision
+within seven days is a target, not a guaranteed deadline. Details in [CONTRIBUTING.md](../CONTRIBUTING.md).