Refine parameter help

[schlusslicht]

This pull request is inspired by, contains and supersedes #123.

Inspired by the pull request opened by @Querela, this pull request contains minimal docstrings for all kosh.params which will be displayed when calling the kosh python entrypoint with the --help parameter. It further refines the implementation provided by the pull request #123 to include not only values of parameters specified on the CLI together with the --help parameter, but all available (as in default) parameter values. Last but not least, the commit f340866 drops the "".format() string formatting function in favour of literal string interpolation (f"").

[schlusslicht]

Output:

# kosh --help
2023-07-11 15:15:13 [INFO] <kosh.kosh> Started kosh with pid 297
2023-07-11 15:15:13 [INFO] <kosh.kosh> Loaded API endpoint modules ['graphql', 'restful']
kosh - APIs for Lexical Data
----------------------------

Parameters:
    --api_port     The port kosh will listen on (set to: 5000)
    --api_root     The API context path kosh will serve (set to: /api)
    --config_file  The configuration file kosh will use 
    --config_text  Arbitrary configuration values kosh will use 
    --data_host    The Elasticsearch host kosh will use (set to: 127.0.0.1)
    --data_pool    String prefix to pool all Elasticsearch indices together (set to: kosh)
    --data_root    The path to XML lexical data with kosh files (set to: /var/lib/kosh)
    --data_sync    The interval in which files are checked for changes (set to: 10)
    --help         Show this help and list available parameters 
    --log_file     Specifies the the file kosh will log to 
    --log_level    Specifies the kosh logger level (set to: INFO)

Loaded API endpoint modules:
    graphql - A GraphQL endpoint serving lexical data
    restful - A RESTful endpoint serving lexical data

[schlusslicht]

Rebased against current master.

[lguenth]

This looks great and everything seems to work as expected with the help parameter itself. It correctly reads values from the config as well, so I'll approve and merge.
As a side note though, while trying to test each parameter again, I think I found a problem with the data_sync setting. I'll open an issue and tag you.