Use proper syntax for replaceables in command docs

The standard for command documentation synopses appears to be:

  [...] means optional
  <...> means replaceable
  [<...>] means both optional and replaceable

So fix a number of doc pages that use incorrect variations of the
above.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/git-cvsserver.txt b/Documentation/git-cvsserver.txt
index 37b96c5..f98b7c6 100644
--- a/Documentation/git-cvsserver.txt
+++ b/Documentation/git-cvsserver.txt
@@ -22,7 +22,7 @@
 Usage:
 
 [verse]
-'git-cvsserver' [options] [pserver|server] [<directory> ...]
+'git-cvsserver' [<options>] [pserver|server] [<directory> ...]
 
 OPTIONS
 -------