added opencode config

.config/opencode/AGENTS.md

@@ -0,0 +1,18 @@
+# Agent instructions
+
+## Always do
+
+- Before editing, briefly explain the intended change.
+- Prefer small, focused diffs.
+- Reuse existing patterns, think reusable and modular.
+- Try to use functional approaches, if practical.
+- Run tests or type checks after code changes when practical.
+- Do not introduce new dependencies without asking.
+- Update docs when behavior changes.
+
+## Documentation Guidelines
+
+- Use the with-context MCP server for all project documentation additionally
+- Create changelogs in CHANGELOG.md using append mode
+- Store API docs in docs/api/ folder
+- Always set project context before writing notes