[Docs] Typo or missing import for Context

[nsteinmetz]

Hello,

Starting to implement streaq in replacement of arq, I think there is a small typo in the doc or a missing import.

from contextlib import asynccontextmanager
from typing import AsyncIterator
from streaq import Worker
from dataclasses import dataclass
from httpx import AsyncClient

@dataclass
class WorkerContext:
    """
    Type safe way of defining the dependencies of your tasks.
    e.g. HTTP client, database connection, settings.
    """
    http_client: AsyncClient

@asynccontextmanager
async def lifespan() -> AsyncIterator[WorkerContext]:
    # here we run code if desired after worker start up
    # yield our dependencies as an instance of the class
    async with AsyncClient() as http_client:
        yield Context(http_client)
    # here we run code if desired before worker shutdown

But Context does not exist - so either it's WorkerContext or Context import is missing.

I would assume, it should be read as:

@asynccontextmanager
async def lifespan() -> AsyncIterator[WorkerContext]:
    # here we run code if desired after worker start up
    # yield our dependencies as an instance of the class
    async with AsyncClient() as http_client:
        yield WorkerContext(http_client)
    # here we run code if desired before worker shutdown

If you confirm, I can make a PR to update the docs accordingly.

[Graeme22]

That's right, PR appreciated!

[nsteinmetz]

Fix is in #78 with the fix for #77