2.29.0: Highlight merge commits

Before this release, they were just ugly. Now they are informatively highlighted!

Support highlighting conflict markers

Conflict markers can be added to files by git merge for example.

Try it:

riff < file-with-conflicts.txt

2.27.1: Don't require file names with -b

Fixes #54.

2.27.0: Fix a crash

Before this release, if you removed a line starting with "--" and passed
the diff to riff, riff would crash. This has been fixed.

Ref: https://github.com/walles/riff/issues/51

As a side effect, riff will now be pickier with its input. If you modify
your diffs manually, beware.

2.26.0: Add -f flag for specifying a diff file to highlight

With this release there are two ways of highlighting a particular diff
file:

  riff < file.diff
  riff --file=file.diff

Command line parsing has been updated to use Clap, which will make help
output look somewhat different. Should also fix some options parsing
corner cases.

2.25.2: Fix rename rendering on some terminals

Before this change, rename rendering on GNOME Terminal for example could
render as grey on green, which was hard to read.

With this release, those renames now render as black on green on all
terminals.

2.25.1: Fix non-leading-tabs highlighting

Also, this release improves (the already good) performance by about 25%.

2.25.0: Highlight file name changes

So with this release, if you have renamed any files, the name changes
will be highlighted in inverse red / green.

2.24.0: New highlighting when there are only additions

Ref: https://github.com/walles/riff/issues/42

2.23.4: Use isatty() from standard library

Before this change we used the atty library, but atty is now
unmaintained.