[PATCH] docs: describe ui.color consistently with --color

[Martin von Zweigbergk]

# HG changeset patch
# User Martin von Zweigbergk <martinvonz at google.com>
# Date 1493661850 25200
#      Mon May 01 11:04:10 2017 -0700
# Branch stable
# Node ID ef67051c82570df534f8947c692dbd1aba274b23
# Parent  0d892d820a51e8ea6261d788d167e54c1d9ed8de
docs: describe ui.color consistently with --color

The --color option is described to accept "boolean, always, auto,
never, or debug". Let's use a similar description for ui.color. Also
fix the formatting to use double quotes as we seem to use for about
half the values in config.txt (the other half uses double
backticks). Also use uppercase Boolean for consistency within the
file.

diff --git a/mercurial/help/config.txt b/mercurial/help/config.txt
--- a/mercurial/help/config.txt
+++ b/mercurial/help/config.txt
@@ -1860,11 +1860,9 @@
     By default, the first bundle advertised by the server is used.
 
 ``color``
-    String: when to use to colorize output. possible value are auto, always,
-    never, or debug (default: auto). 'auto' will use color whenever it seems
-    possible. See :hg:`help color` for details.
-
-    (in addition a boolean can be used in place always/never)
+    When to colorize output. Possible value are Boolean, "always", "auto",
+    "never", or "debug". (default: "auto"). "auto" will use color
+    whenever it seems possible. See :hg:`help color` for details.
 
 ``commitsubrepos``
     Whether to commit modified subrepositories when committing the