docs: Add clarification for projects using 'opencode' name

Added a section to clarify the affiliation of related projects.

Author: jayair

README.md

@@ -59,6 +59,10 @@ For more info on how to configure OpenCode [**head over to our docs**](https://o
 
 If you're interested in contributing to OpenCode, please read our [contributing docs](./CONTRIBUTING.md) before submitting a pull request.
 
+### Building on OpenCode
+
+If you are working on a project that's related to OpenCode and is using "opencode" as a part of its name; for example, "opencode-dashboard" or "opencode-mobile", please add a note to your README to clarify that it is not built by the OpenCode team and is not affiliated with us in anyway.
+
 ### FAQ
 
 #### How is this different than Claude Code?