Clarify in/exclusiveness of bounds of selection when comparing commits

[ravindUwU]

The FAQ explains how 2 commits can be compared by Ctrl-clicking them: https://github.com/fork-dev/Docs/blob/8d49ab70c2a231bf55a84334a5bda97b397e2c89/faq.md#how-to-compare-two-branches-or-commits

I think it'd also be useful to clarify,

• Whether the order of selection matters.
  The selected commits seem always compared in chronological order.
  With the Git CLI, one can do git diff start end and git diff start end to get opposite diffs. In these terms, Fork always does git diff start end.

• Whether the selection is start/end commit inclusive/excluve.
  The selection seems start-exclusive, end-inclusive, similar to Git.