config: add a new [command-templates] section for templates defined by hg The existing `[templates]` section lets the user define their own keys and then refer to them on the command line with `-T`. There are many cases where hg wants to use a user-defined template with a given name, such as `ui.logtemplate` and `ui.mergemarkertemplate`. This patch starts moving such configs in a common section by moving `ui.logtemplate` to `command-templates.log` (with an alias from the old name, of course). Differential Revision: https://phab.mercurial-scm.org/D9245

--- a/tests/test-amend.t	Mon Oct 26 10:08:22 2020 -0700
+++ b/tests/test-amend.t	Fri Oct 23 10:56:18 2020 -0700
@@ -403,10 +403,10 @@
   $ hg init $TESTTMP/repo5
   $ cd $TESTTMP/repo5
   $ cat <<'EOF' >> .hg/hgrc
-  > [ui]
-  > logtemplate = 'user:        {user}
-  >                date:        {date|date}
-  >                summary:     {desc|firstline}\n'
+  > [command-templates]
+  > log = 'user:        {user}
+  >        date:        {date|date}
+  >        summary:     {desc|firstline}\n'
   > EOF
 
   $ echo a>a