Reword on goto_change shortcut keys

[hongquan]

The old wording is confusing.

[leandrobbraga]

I do believe that the idea of the previous naming is to be VCS agnostic, change seems a little bit too vague, but I can't think in a better name right now to suggest

[hongquan]

At first, I didn't understand what it means, until I found the blog post about Helix's Git support.
I think, in the future, when Helix supports more VCS, it can be named "Goto VCS change/hunk". For now, Helix only supports Git and it is more obvious to say "Go to Git hunk".

[pascalkuthe]

• we plan to support other VCS in the future (as plugins) so Git should not be mentioned explicitly
• we will allow diffing against arbitrary files and Buffets (a PR is already open) so it should not mention VCS either

These were designed goals from the start which is why I chose the current description. The most I would co sidereal is to use diff change instead of change.

These also aren't the rendered docs. Those should be adjusted to match

[hongquan]

Thanks. I will close this PR and wait for Helix update.