fix "patterns" help formatting, too

this way it renders nicely in html (via sphinx) and on console

borg/archiver.py

@@ -773,35 +773,35 @@ class Archiver:
         whitespace removal paths with whitespace at the beginning or end can only be
         excluded using regular expressions.
 
-        Examples:
-
-        # Exclude '/home/user/file.o' but not '/home/user/file.odt':
-        $ borg create -e '*.o' backup /
-
-        # Exclude '/home/user/junk' and '/home/user/subdir/junk' but
-        # not '/home/user/importantjunk' or '/etc/junk':
-        $ borg create -e '/home/*/junk' backup /
-
-        # Exclude the contents of '/home/user/cache' but not the directory itself:
-        $ borg create -e /home/user/cache/ backup /
-
-        # The file '/home/user/cache/important' is *not* backed up:
-        $ borg create -e /home/user/cache/ backup / /home/user/cache/important
-
-        # The contents of directories in '/home' are not backed up when their name
-        # ends in '.tmp'
-        $ borg create --exclude 're:^/home/[^/]+\.tmp/' backup /
-
-        # Load exclusions from file
-        $ cat >exclude.txt <<EOF
-        # Comment line
-        /home/*/junk
-        *.tmp
-        fm:aa:something/*
-        re:^/home/[^/]\.tmp/
-        sh:/home/*/.thumbnails
-        EOF
-        $ borg create --exclude-from exclude.txt backup /
+        Examples::
+
+            # Exclude '/home/user/file.o' but not '/home/user/file.odt':
+            $ borg create -e '*.o' backup /
+
+            # Exclude '/home/user/junk' and '/home/user/subdir/junk' but
+            # not '/home/user/importantjunk' or '/etc/junk':
+            $ borg create -e '/home/*/junk' backup /
+
+            # Exclude the contents of '/home/user/cache' but not the directory itself:
+            $ borg create -e /home/user/cache/ backup /
+
+            # The file '/home/user/cache/important' is *not* backed up:
+            $ borg create -e /home/user/cache/ backup / /home/user/cache/important
+
+            # The contents of directories in '/home' are not backed up when their name
+            # ends in '.tmp'
+            $ borg create --exclude 're:^/home/[^/]+\.tmp/' backup /
+
+            # Load exclusions from file
+            $ cat >exclude.txt <<EOF
+            # Comment line
+            /home/*/junk
+            *.tmp
+            fm:aa:something/*
+            re:^/home/[^/]\.tmp/
+            sh:/home/*/.thumbnails
+            EOF
+            $ borg create --exclude-from exclude.txt backup /
         ''')
     helptext['placeholders'] = textwrap.dedent('''
         Repository (or Archive) URLs and --prefix values support these placeholders: