docs: add README.md

Author: snus-kin

README.md

@@ -0,0 +1,46 @@
+# Athena Client Library
+
+This is a Python library for interacting with the Athena API (Resolver Unknown
+CSAM Detection).
+
+
+## Development
+This package uses [uv](https://docs.astral.sh/uv/) to manage its packages.
+
+To install dependencies, run:
+
+```bash
+uv sync --dev
+```
+
+To build the package, run:
+
+```bash
+uv build
+```
+
+To run the tests, run:
+
+```bash
+pytest
+```
+
+To lint and format the code, run:
+
+```bash
+ruff check
+ruff format
+```
+
+There are pre-commit hooks that will run these commands automatically before
+committing changes. Install them with:
+
+```bash
+pre-commit install
+```
+
+To re-compile the protobuf files, run from the repository's root directory:
+
+```bash
+bash scripts/compile_protobuf.sh
+```