Better logging and documentation support

[GeekMasher]

No description provided.

[zbazztian]

Looks good to me. I left a few comments.

Another note (which doesn't necessarily relate to this PR): Supplying multiple languages via --language is currently broken:

> ./gh-codeql-summarize -p zbazztian/commons-io-public -l java,csharp -o results

...

2022-08-03 15:26:28,120 - codeqlsummarize.generator - INFO - Finding query name: SinkModel
2022-08-03 15:26:28,120 - codeqlsummarize.generator - INFO - Running Query :: codeql/csharp-queries:utils/model-generator/CaptureSinkModels.ql
Running query "codeql/csharp-queries:utils/model-generator/CaptureSinkModels.ql"...
Traceback (most recent call last):
  File "/usr/lib/python3.10/runpy.py", line 196, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/lib/python3.10/runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "/home/sebastian/dev/src/gh-codeql-summarize/codeqlsummarize/__main__.py", line 209, in <module>
    main(arguments)
  File "/home/sebastian/dev/src/gh-codeql-summarize/codeqlsummarize/__main__.py", line 193, in main
    database.summaries[name] = generator.runQuery(query_path)
  File "/home/sebastian/dev/src/gh-codeql-summarize/codeqlsummarize/generator.py", line 74, in runQuery
    self.codeql(
  File "/home/sebastian/dev/src/gh-codeql-summarize/codeqlsummarize/utils.py", line 152, in __call__
    raise CalledProcessError(cmd=commandstr, returncode=ret)
subprocess.CalledProcessError: Command '/home/sebastian/.local/share/gh/extensions/gh-codeql/dist/release/v2.9.4/codeql database run-queries --threads 0 /tmp/codeqlsummarize/zbazztian_commons-io-public/java codeql/csharp-queries:utils/model-generator/CaptureSinkModels.ql' returned non-zero exit status 2.

Do we really want to allow supplying multiple languages? I'd say most callers know for which languages they want the customizations, which would make the implementation much easier for us. Also, I retract my suggestion of making --language optional. I guess most of the time one would point this tool to a repository which would definitely require specifying the language one wants the summaries for anyway.

[zbazztian]

lgtm