docs: clarify pattern usage with commands (#5959)

docs: clarify pattern usage with commands, fixes #5176

docs/usage/list.rst

@@ -31,4 +31,14 @@ Examples
     drwxrwxr-x user   user          0 Sun, 2015-02-01 11:00:00 code
     drwxrwxr-x user   user          0 Sun, 2015-02-01 11:00:00 code/myproject
     -rw-rw-r-- user   user    1416192 Sun, 2015-02-01 11:00:00 code/myproject/file.ext
+    -rw-rw-r-- user   user    1416192 Sun, 2015-02-01 11:00:00 code/myproject/file.text
+    ...
+
+    $ borg list /path/to/repo/::archiveA --pattern 're:\.ext$'
+    -rw-rw-r-- user   user    1416192 Sun, 2015-02-01 11:00:00 code/myproject/file.ext
+    ...
+
+    $ borg list /path/to/repo/::archiveA --pattern 're:.ext$'
+    -rw-rw-r-- user   user    1416192 Sun, 2015-02-01 11:00:00 code/myproject/file.ext
+    -rw-rw-r-- user   user    1416192 Sun, 2015-02-01 11:00:00 code/myproject/file.text
     ...

src/borg/archiver.py

@@ -2230,7 +2230,9 @@ class Archiver:
         File patterns support these styles: fnmatch, shell, regular expressions,
         path prefixes and path full-matches. By default, fnmatch is used for
         ``--exclude`` patterns and shell-style is used for the experimental
-        ``--pattern`` option.
+        ``--pattern`` option. For commands that support patterns in their
+        ``PATH`` argument like (``borg list``), the default pattern is path
+        prefix.
 
         Starting with Borg 1.2, for all but regular expression pattern matching
         styles, all paths are treated as relative, meaning that a leading path