CONTRIBUTING.md: Update formatting requirements.

Also point to contrib/format.sh as the source of truth.

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 791446a..11969de 100644 (file)
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -30,9 +30,11 @@ the mailing list have a tendency to fall through the cracks.
 
 *   *Focus:* Fix *one thing* in your PR. The smaller your change, the faster it
     will be reviewed and merged.
-*   *Coding style:* Please run `clang-format -style=file -i $FILE` on new files.
-    For existing files, please blend into surrounding code, i.e. mimic the
-    coding style of the code around your changes.
+*   *Coding style:* Please run `clang-format -style=file -i $FILE` after editing
+    `.c`, `.h` and `.proto` files. If you don't want to install *clang-format*
+    locally or your version produces a different result than the formatting
+    check on Github, use `contrib/format.sh` to format files using the same web
+    service used by our check.
 *   *Documentation:* New config options need to be documented in two places: the
     manpage (`src/collectd.conf.pod`) and the example config
     (`src/collectd.conf.in`). New plugins need to be added to the `README` file.