Add content menu items not only to the files in "Workspace" area

[Mingun]

This is inconvenient -- sometimes you want to open a file not from the workspace, but neither the tab menu nor the "Open Editors" menu have any extension menu items.

In any case I suggest to rework how extension is work. Just add one command "Parse with KSY" that will apply to the active buffer. In that command ask what KSY to use. I suggest to show selector (similery to the select command "Ctrl+Shift+P") with variants:

• Configured (see below)
• Open KSY file...
• <...list of opened editors...>

Also add extension setting with KSY associations to the file glob patterns (usually something like "<ksy path>": "*.ext"). Show this variant as "Configured"