docs: add AGENTS instructions and development workflow guidelines in AGENTS.md

Author: kosiew

AGENTS.md

@@ -0,0 +1,24 @@
+# AGENTS Instructions
+
+This repository contains Python bindings for Rust's DataFusion.
+
+## Development workflow
+- Ensure git submodules are initialized: `git submodule update --init`.
+- Build the Rust extension before running tests:
+  - `uv run --no-project maturin develop --uv`
+- Run tests with pytest:
+  - `uv --no-project pytest .`
+
+## Linting and formatting
+- Use pre-commit for linting/formatting.
+- Run hooks for changed files before committing:
+  - `pre-commit run --files <files>`
+  - or `pre-commit run --all-files`
+- Hooks enforce:
+  - Python linting/formatting via Ruff
+  - Rust formatting via `cargo fmt`
+  - Rust linting via `cargo clippy`
+
+## Notes
+- The repository mixes Python and Rust; ensure changes build for both languages.
+- If adding new dependencies, update `pyproject.toml` and run `uv sync --dev --no-install-package datafusion`.