Change "Command Line Grammar" wiki page

[VewDev]

Change "Command Line Grammar" wiki page to be more descriptive about the default behaviour of a "switch option".

I would suggest changing line 77 from:

// CheckIn = true by default to: // CheckIn = if passed to the command line, it will be true by default

since the default value of a switch option is false unless passed to the command line.

Inspired by the confusion of the user in #916

Opening an issue instead of a PR since PR to wiki pages is not supported