i3 pin-workspaces behaviour for a named monitor output.

[sumebrius]

What type of PR is this? (check all applicable)

• Refactor
• Feature
• Bug Fix
• Optimization
• Documentation Update
• Other: Replace this with a description of the type of this PR

Description

Adds a new configuration for module i3:

• pin-output - If pin-workspaces is set, will pin workspaces associated with the named monitor instead of the current monitor

Related Issues & Documents

Closes #1625

Documentation (check all applicable)

• This PR requires changes to the Wiki documentation (describe the changes)
• This PR requires changes to the documentation inside the git repo (please add them to the PR).
• Does not require documentation changes

Documentation to be added to i3 module page - under description of pin-output configuration:

; Pin workspaces defined on monitor 'DP-1' instead of the same output as the bar
;
; Default: empty
pin-output = DP-1

[patrick96]

Should pin-output imply pin-workspaces? Seems more user-friendly.