update tom_alertstreams for LSST

[phycodurus]

Now that the LSST alertstreams are live, we should:

• document how to receive each stream in the README.md (i.e. There should be sample configuration dictionaries for each of the following alert streams in the README), and
• demonstrate how to receive each of the alert streams in tom-demo.

LSST streams

Alert stream	README example	working in tom-demo	working locally
ALeRCE	☐	☐	☐
AMPEL	☐	☐	☐
ANTARES	☐	☐	☑
Babamol	☐	☐	☑
Fink	☐	☐	☑
Lasair	☐	☐	☑
Pitt-Google	☐	☐	☐

Non-LSST streams:

Alert stream	README example	working in tom-demo	working locally
GCN	☐	☐	☐
SCiMMA	☐	☐	☐

Other TODOs:

• move this issue to the tom_alertstreams repo
• make sure installation instructions are clear wrt individual client packages needing to be specified; and that installation will be in the context of a requirements.txt or pyproject.toml file.

sub-issues

• demo ALeRCE LSST alert stream
• demo AMPEL LSST alert stream
• demo ANTARES LSST alert stream
• demo Babmol LSST alert stream
• demo Fink LSST alert stream
• demo Lasair LSST alert stream
• demo Pitt-Google LSST alert stream
• demo GCN LSST alert stream
• demo SCiMMa LSST alert stream