Dynamically insert default configuration parameters

[voetberg]

Addressing #325

Creates a json file from opt/rucio/rucio.cfg which is read by configuration_parameters.mdx for each section/option. Includes the parameter if the field is in the config, or else just puts in "No default."

[rdimaio]

Looks good, thanks for doing this. I wonder if we could go a step further and generate the doc page so that the config sections and parameter names are also automatically pulled from the example cfg files, to avoid having to manually maintain this at all

[rdimaio]

These values atlas, belleii, cms... are specific to those experiments, so I don't think they should be included here

[voetberg]

Looks good, thanks for doing this. I wonder if we could go a step further and generate the doc page so that the config sections and parameter names are also automatically pulled from the example cfg files, to avoid having to manually maintain this at all

I like that idea a lot, I don't think it would be too hard to swing. I am worried that it would shift the work of documentation to the config file instead of the md file (not all the parameters are in the config file to begin with - view this log).