feat(python): Document default span attrs in aiohttp, update for 3.0 (#14363)

Document what span attributes will be attached to transactions by
default by our builtin integrations. This PR updates AIOHTTP. Rest will
follow.

I created a new 3.x page for this since it's new behavior in 3.0.

Author: sentrivana

docs/platforms/python/integrations/aiohttp/index__v3.x.mdx

@@ -0,0 +1,118 @@
+---
+title: AIOHTTP
+description: "Learn about using Sentry with AIOHTTP."
+---
+
+The AIOHTTP integration adds support for the [AIOHTTP server web framework](https://docs.aiohttp.org/en/stable/web.html).
+
+If you use AIOHTTP as your HTTP client and want to instrument outgoing HTTP requests, have a look at the <PlatformLink to="/integrations/aiohttp/aiohttp-client/">AIOHTTP client documentation</PlatformLink>.
+
+## Install
+
+Install `sentry-sdk` from PyPI with the `aiohttp` extra:
+
+```bash {tabTitle:pip}
+pip install "sentry-sdk[aiohttp]"
+```
+```bash {tabTitle:uv}
+uv add "sentry-sdk[aiohttp]"
+```
+
+## Configure
+
+If you have the `aiohttp` package in your dependencies, the AIOHTTP integration will be enabled automatically when you initialize the Sentry SDK.
+
+<PlatformContent includePath="getting-started-config" />
+
+## Verify
+
+```python
+from aiohttp import web
+
+sentry_sdk.init(...)  # same as above
+
+async def hello(request):
+    1 / 0  # raises an error
+    return web.Response(text="Hello, world")
+
+app = web.Application()
+app.add_routes([web.get('/', hello)])
+
+web.run_app(app)
+```
+
+When you point your browser to [http://localhost:8080/](http://localhost:8080/) a transaction will be created in the Performance section of [sentry.io](https://sentry.io). Additionally, an error event will be sent to [sentry.io](https://sentry.io) and will be connected to the transaction.
+
+It takes a couple of moments for the data to appear in [sentry.io](https://sentry.io).
+
+## Behavior
+
+- The Sentry Python SDK will install the AIOHTTP integration for all of your apps.
+- All exceptions leading to an Internal Server Error are reported.
+- _The AIOHTTP integration currently does not attach the request body_, see [GitHub issue](https://github.com/getsentry/sentry-python/issues/220).
+- Logging with any logger will create breadcrumbs when the [Logging](/platforms/python/integrations/logging/) integration is enabled (done by default).
+
+### Tracing
+
+A set of predefined span attributes will be attached to AIOHTTP transactions by default. These can also be used for sampling since they will also be accessible via the `sampling_context` dictionary in the [`traces_sampler`](/platforms/python/configuration/options/#traces_sampler).
+
+- `url.path`
+- `url.query`
+- `url.scheme`
+- `url.full`
+- `http.request.method`
+- `http.request.header.{header}`
+- `server.address`
+- `server.port`
+
+These attributes will also be sent to Sentry. If you don't want that, you can filter them out using a custom [`before_send`](/platforms/python/configuration/options/#before_send) function.
+
+## Options
+
+By adding `AioHttpIntegration` to your `sentry_sdk.init()` call explicitly, you can set options for `AioHttpIntegration` to change its behavior:
+
+```python
+import sentry_sdk
+from sentry_sdk.integrations.aiohttp import AioHttpIntegration
+
+sentry_sdk.init(
+    # same as above
+    integrations=[
+        AioHttpIntegration(
+            transaction_style="...",  # type: str
+            failed_request_status_codes={...}  # type: collections.abc.Set[int]
+        ),
+    ],
+)
+```
+
+You can pass the following keyword arguments to `AioHttpIntegration()`:
+
+### `transaction_style`
+
+Configure the way Sentry names transactions:
+
+- `GET /path/{id}` if you set `transaction_style="method_and_path_pattern"`
+- `<module_name>.hello` if you set `transaction_style="handler_name"`
+
+The default is `"handler_name"`.
+
+### `failed_request_status_codes`
+
+A `set` of integers that will determine when an `HTTPException` should be reported to Sentry. The `HTTPException` is reported to Sentry if its status code is contained in the `failed_request_status_codes` set.
+
+Examples of valid `failed_request_status_codes`:
+
+- `{500}` will only report `HTTPException` with status 500 (i.e. `HTTPInternalServerError`).
+- `{400, *range(500, 600)}` will report `HTTPException` with status 400 (i.e. `HTTPBadRequest`) as well as those in the 5xx range.
+- `set()` (the empty set) will not report any `HTTPException` to Sentry.
+
+The default is `{*range(500, 600)}`, meaning that any `HTTPException` with a status in the 5xx range is reported to Sentry.
+
+Regardless of how `failed_request_status_codes` is set, any exceptions raised by the handler, which are not of type `HTTPException` (or a subclass) are reported to Sentry. For example, if your request handler raises an unhandled `AttributeError`, the `AttributeError` gets reported to Sentry, even if you have set `failed_request_status_codes=set()`.
+
+
+## Supported Versions
+
+- AIOHTTP: 3.5+
+- Python: 3.7+