Document a bit

README.md

@@ -1 +1,59 @@
 # asyncpg-engine
+
+Little wrapper around [asyncpg](https://github.com/MagicStack/asyncpg) for specific experience.
+
+[![Build Status](https://github.com/sivakov512/asyncpg-engine/actions/workflows/test.yml/badge.svg)](https://github.com/sivakov512/asyncpg-engine/actions/workflows/test.yml)
+[![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)
+[![Python versions](https://img.shields.io/pypi/pyversions/asyncpg-engine.svg)](https://pypi.python.org/pypi/asyncpg-engine)
+[![PyPi](https://img.shields.io/pypi/v/asyncpg-engine.svg)](https://pypi.python.org/pypi/asyncpg-engine)
+
+## Basic usage
+
+```python
+from asyncpg_engine import Engine
+
+
+engine = await Engine.create("postgres://guest:guest@localhost:5432/guest?sslmode=disable")
+
+async with engine.acquire() as con:
+    # https://magicstack.github.io/asyncpg/current/api/index.html#asyncpg.connection.Connection
+    assert await con.fetchval("SELECT 1") == 1
+```
+
+### Custom type conversions
+
+You can specify [custom encoder\decoder](https://magicstack.github.io/asyncpg/current/usage.html#custom-type-conversions) by subclassing `Engine`:
+```python
+from asyncpg_engine import Engine
+import orjson
+
+
+class MyEngine(Engine):
+
+    @staticmethod
+    async def _set_codecs(con: Connection) -> None:
+        # https://magicstack.github.io/asyncpg/current/api/index.html#asyncpg.connection.Connection.set_type_codec
+        await con.set_type_codec(
+            "json", encoder=orjson.dumps, decoder=orjson.loads, schema="pg_catalog"
+        )
+```
+
+## Development and contribution
+
+First of all you should install Poetry using [official instructions](https://python-poetry.org/docs/#osx--linux--bashonwindows-install-instructions) or solutions provided by your distro. Then install dependencies:
+```bash
+poetry install
+```
+
+Run PostgreSQL using provided docker-compose configuration:
+```bash
+docker-compose up  # run it in another terminal or add `-d` to daemonize
+```
+
+Project uses combination of `flake8`, `black`, `isort` and `mypy` for linting and `pytest` for testing.
+
+```bash
+poetry run flake8
+poetry run mypy ./
+poetry run pytest
+```