[PATCH 3 of 3] revset: point to 'grep' in the 'keyword' help for regex searches

[Matt Harbison]

# HG changeset patch
# User Matt Harbison <matt_harbison at yahoo.com>
# Date 1484194431 18000
#      Wed Jan 11 23:13:51 2017 -0500
# Node ID 1d88ac8809e20256e3702f25c77a411a53367474
# Parent  41eac69037f03733374ea658a6a13de3973860bc
revset: point to 'grep' in the 'keyword' help for regex searches

The help for 'grep' already points to 'keyword'.

diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -1253,6 +1253,9 @@
 def keyword(repo, subset, x):
     """Search commit message, user name, and names of changed files for
     string. The match is case-insensitive.
+
+    For a regular expression or case sensitive search of these fields, use
+    ``grep(regex)``.
     """
     # i18n: "keyword" is a keyword
     kw = encoding.lower(getstring(x, _("keyword requires a string")))