[Settings] Re-phrase column headers for clarity

[Jay-o-Way]

Seen more then one issue where somebody mixed up the column of shortcuts. When looking at it again, the left one says "shortcut" which can be interpreted as both "key press" (like keyboard input) or "output" (which = OS input). The words "mapped to" say nothing about "on which end", it could also mean "mapped to physical keys". We can solve this by using better words.

left column	right column
Keyboard input	Output (still ambigous)
Key press(es)	Resulting shortcut
Press [...]	to send [...]
physical	digital
...	...

We should also check the explaining text to be up-to-date, while at it.

I guess this is a sub-item for #2027

@Jay-o-Way Oh man I feel stupid now lol. I had it backwards.
Might be worth clarifying which column is which for vacant minded people like myself haha.
Thanks a bunch for your guys help. Working fine now :)

Originally posted by @rmcguinn in #13623 (comment)

[niels9001]

Agree. The whole KBM (including its settings) should get an overhaul to be more self-explainatory and easier to use.

[Jay-o-Way]

If ui changed, naturally #docs should follow

[crutkas]

/dup #10389

[ghost]

Hi! We've identified this issue as a duplicate of another one that already exists on this Issue Tracker. This specific instance is being closed in favor of tracking the concern over on the referenced thread. Thanks for your report!