Add notes about debugging HA in Dev Container

[dgtal1]

Since some people (like me and others) experience issues with the default Dev Container debugging, which doesn't work out-of-the box - new developers may think that debugging is not supported by the dev container out-of-the-box. This description is to indicate that normally debugging doesn't need any additional actions to be taken to enable it. I also mentioned the way to debug remote instances, which may be very helpful for the developers, also in case of issues with the default debugging without enabling debugpy. If I had such description I wouldn't loose almost 2 hours of googling trying to find out what is supported and what are the options, so I hope thanks to this people will avoid this.

Proposed change

As above. This is not covered by the docs, and people may think debugging in devcontainer is not supported by default, especially if it doesn't work for them (for some it doesn't work).

Type of change

• [X] Document existing features within Home Assistant
• [ ] Document new or changing features which there is an existing pull request elsewhere
• [ ] Spelling or grammatical corrections, or rewording for improved clarity
• [ ] Changes to the backend of this documentation
• [ ] Removed stale or deprecated documentation

Additional information

• This PR fixes or closes issue: fixes #
• Link to relevant existing code or pull request: