Add documentation microagent (#8563)

Co-authored-by: openhands <openhands@all-hands.dev>

.openhands/microagents/documentation.md

@@ -0,0 +1,33 @@
+---
+name: documentation
+type: knowledge
+version: 1.0.0
+agent: CodeActAgent
+triggers:
+- documentation
+- docs
+- document
+---
+
+# Documentation Guidelines
+
+All documentation must be grounded in fact, so you must not make anything up without proper evidence. When you have finished writing documentation, convey to the user what reference source, including web pages, source code, or other sources of documentation you referenced when writing each new fact in the documentation. If you cannot reference a source for anything do not include it in the pull request.
+
+## Best Practices for Documentation
+
+1. **Be Factual**: Only include information that can be verified from reliable sources.
+2. **Cite Sources**: Always reference the source of information (code, web pages, official documentation).
+3. **Be Clear and Concise**: Use simple language and avoid unnecessary jargon.
+4. **Use Examples**: Include practical examples to illustrate concepts.
+5. **Structure Properly**: Use headings, lists, and code blocks to organize information.
+6. **Keep Updated**: Ensure documentation reflects the current state of the code or system.
+
+## Documentation Process
+
+1. Research and gather information from reliable sources
+2. Draft documentation based on verified facts
+3. Review for accuracy and completeness
+4. Include references for all factual statements
+5. Submit only when all information is properly sourced
+
+Remember: If you cannot verify a piece of information, it's better to exclude it than to include potentially incorrect information.