Remove unneeded doc generation script

[lukaspie]

This script is not needed anymore with the new mechanism in #411. Just forgot to remove it.

[RubelMozumder]

I see the dataconverter_help_output.md file has also been removed. Just a question, do you have other script that will automatically update the docs for --help output?

[lukaspie]

I see the dataconverter_help_output.md file has also been removed. Just a question, do you have other script that will automatically update the docs for --help output?

These now get autogenerated, e.g. on this page using mkdocs-click (see relevant changes in #411). This is so much cleaner than having to run this script every time.