WebSocket KeepAlive section improvements

### Describe the issue or suggestion

Follow-ups from https://github.com/dotnet/docs/pull/44611

- [ ] 1. Use xrefs (https://github.com/dotnet/docs/pull/44611#discussion_r1934721615, https://github.com/dotnet/docs/pull/44611#discussion_r1934739933, https://github.com/dotnet/docs/pull/44611#discussion_r1934740231)

- [ ] 1.1.

https://github.com/dotnet/docs/blob/3b05c5f672da7c7a32b041d9be4992e2cbd83a00/docs/fundamentals/networking/websockets.md?plain=1#L109-L116

It would be better to use `` here instead of code blocks.

- [ ] 1.2.

https://github.com/dotnet/docs/blob/3b05c5f672da7c7a32b041d9be4992e2cbd83a00/docs/fundamentals/networking/websockets.md?plain=1#L169

```diff
> Currently, `WebSocket` ONLY processes incoming frames while there's a task pending.
```

- [ ] 1.3.

https://github.com/dotnet/docs/blob/3b05c5f672da7c7a32b041d9be4992e2cbd83a00/docs/fundamentals/networking/websockets.md?plain=1#L156

```suggestion
If the timeout elapses, an outstanding throws an :
```

- [ ] 2. Reword to clarify this is an implication (https://github.com/dotnet/docs/pull/44611#discussion_r1934731319)

https://github.com/dotnet/docs/blob/3b05c5f672da7c7a32b041d9be4992e2cbd83a00/docs/fundamentals/networking/websockets.md?plain=1#L122

Would be good suggest that this is an implication of the behavior described before.

```suggestion
As a result, overriding is enough to switch to the PING/PONG strategy if you keep the default value for :
```

- [ ] 3. Reword sentence conjunctions (https://github.com/dotnet/docs/pull/44611#discussion_r1934743185)

https://github.com/dotnet/docs/blob/3b05c5f672da7c7a32b041d9be4992e2cbd83a00/docs/fundamentals/networking/websockets.md?plain=1#L172

```suggestion
> If you want to use Keep-Alive Timeout, it's _crucial_ that PONG responses are _promptly processed_. Even when the remote endpoint is alive and properly sends the PONG response, if the `WebSocket` isn't processing the incoming frames, the Keep-Alive mechanism can issue a "false-positive" Abort. This problem can happen if the PONG frame is never picked up from the transport stream before the timeout elapsed.
```

- [ ] 4. Fix typo (#44952)

There is a sentence that starts about two thirds of the way through the "Keep-Alive strategies" section of the article that begins "They sent regularly with KeepAliveInterval intervals...". Nothing major but I think "They sent" should probably be "They are sent".