From: Julia Evans <julia@jvns.ca>

The top piece of feedback users always give about man pages is always
that they want better examples that are relevant to them.

The EXAMPLES section's structure has remained mostly unchanged since
2007, which was before we knew how people were going to use `git diff`.
Update it with ways of using `git diff` that are popular with Git
users, gathered by asking Mastodon users for their most commonly used
incantations.

Add a note about the EXAMPLES section in the DESCRIPTION since otherwise
readers are unlikely to know it's there. `git diff` is a command where
it's more important than usual to have examples because the command has
so many different forms.

Some design choices:

- Use `--merge-base` instead of `...` since several users said they
  find .. vs ... confusing. It's much more obvious what --merge-base
  does.
- Use a table format instead of the footnote-style formatting since the
  footnote style is quite difficult to follow. It's easier to follow
  if the description is right next to the command it's describing.
- Link the options in the examples to make them faster to look up
- Use sub-subsection headings for the different parts to make
  them more visually distinct and easy to scan.

Co-Authored-By: Marie Claire LeBlanc Flanagan <hello@marieflanagan.com>
Signed-off-by: Marie Claire LeBlanc Flanagan <hello@marieflanagan.com>
Signed-off-by: Julia Evans <julia@jvns.ca>

Submitted-As: https://lore.kernel.org/git/pull.2293.git.1793720007182.gitgitgadget@gmail.com