Generate commands list as Markdown table

[aslesarenko]

Problem

Each CliApplication implements a list of commands.
This list can be printed in console output as part of usage help message.
However, it is usually required to have this list also in a documentation page.
The corresponding section of the doc page can thus be generated for any CliApplication instance.

Solution

Implement the genMarkdown method which uses commands method for a list of supported commands.

Example