deprecating startnum

[ferdinandyb]

The pull request regolith-linux/regolith-i3xrocks-config#82 will deprecate the --startnum for next-workspace.

[ferdinandyb]

I realized a comment was wrong (Mod1 is Alt not Shift) and that there is a second place where --startnum was used

[moritzheiber]

@ferdinandyb I'm afraid you'll have to rebase

[ferdinandyb]

oh yeah, some time has passed, I'll fix it later

[ferdinandyb]

Note, that 9d260b0 also noted that the comment and the actual command was wrong, but actually, the comment was in error, since we use $mod for "move and follow" maneuvers with the workspace numbers as well.

And I will go ahead and merge now, since the related update with next-workspace is already merged.

[kgilmer]

Beautiful, thank you!