diff-highlight: mention build instructions

Once upon a time, this was just a script in a directory that could be run directly. That changed in 0c977dbc81 (diff-highlight: split code into module, 2017-06-15). Let's update the README to make it more clear that you need to run make. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Mar 23, 2026 at 02:01 UTC 41529f967f919685a3294a9fc4b45140311bebae
1 file changed +12 -1
contrib/diff-highlight/README
+12 -1
@@ -39,10 +39,21 @@ visually distracting. Non-diff lines and existing diff coloration is
39 preserved; the intent is that the output should look exactly the same as
40 the input, except for the occasional highlight.
41
42 +Build/Install
43 +-------------
44 +
45 +You can build the `diff-highlight` script by running `make` from within
46 +the diff-highlight directory. There is no `make install` target; you can
47 +copy the built script to your $PATH.
48 +
49 +You can run diff-highlight's internal tests by running `make test`. Note
50 +that you must also build Git itself first (by running `make` from the
51 +top-level of the project).
52 +
53 Use
54 ---
55
45 -You can try out the diff-highlight program with:
56 +You can try out the built diff-highlight program with:
57
58 ---------------------------------------------
59 git log -p --color | /path/to/diff-highlight