Add documentation on patterns and excludes.

NEWS

@@ -12,6 +12,8 @@
  * #1172: Add an "environment" option to the Sentry monitoring hook.
  * Add a "rename" option to "extra_borg_options" to support passing arbitrary flags to "borg
    rename".
+ * Add documentation on patterns and excludes:
+   https://torsion.org/borgmatic/reference/configuration/patterns-and-excludes/
 
 2.0.10
  * #427: Expand the "extra_borg_options" option to support passing arbitrary Borg flags to every

docs/how-to/set-up-backups.md

@@ -156,6 +156,9 @@ added new options since you originally created your configuration file. Also
 check out how to [upgrade your
 configuration](https://torsion.org/borgmatic/how-to/upgrade/#upgrading-your-configuration).
 
+And see the documentation on [patterns and
+excludes](https://torsion.org/borgmatic/reference/configuration/patterns-and-excludes/).
+
 
 ### Encryption