doc: git-notes.txt: migrate to new documentation format

The git-notes manpage files were converted to the new documentation
format:

- switching the synopsis to a synopsis block which will automatically
  format placeholders in italics and keywords in monospace
- use _<placeholder>_ instead of <placeholder> in the description
- use `backticks for keywords and more complex option
descriptions`. The new rendering engine will apply synopsis rules to
these spans.

Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config/notes.txt

@@ -1,4 +1,4 @@
-notes.mergeStrategy::
+`notes.mergeStrategy`::
 	Which merge strategy to choose by default when resolving notes
 	conflicts.  Must be one of `manual`, `ours`, `theirs`, `union`, or
 	`cat_sort_uniq`.  Defaults to `manual`.  See the "NOTES MERGE STRATEGIES"
@@ -7,17 +7,17 @@ notes.mergeStrategy::
 This setting can be overridden by passing the `--strategy` option to
 linkgit:git-notes[1].
 
-notes.<name>.mergeStrategy::
+`notes.<name>.mergeStrategy`::
 	Which merge strategy to choose when doing a notes merge into
-	refs/notes/<name>.  This overrides the more general
-	"notes.mergeStrategy".  See the "NOTES MERGE STRATEGIES" section in
+	`refs/notes/<name>`.  This overrides the more general
+	`notes.mergeStrategy`.  See the "NOTES MERGE STRATEGIES" section in
 	linkgit:git-notes[1] for more information on the available strategies.
 
-notes.displayRef::
+`notes.displayRef`::
 	Which ref (or refs, if a glob or specified more than once), in
 	addition to the default set by `core.notesRef` or
 	`GIT_NOTES_REF`, to read notes from when showing commit
-	messages with the 'git log' family of commands.
+	messages with the `git log` family of commands.
 +
 This setting can be overridden with the `GIT_NOTES_DISPLAY_REF`
 environment variable, which must be a colon separated list of refs or
@@ -26,35 +26,35 @@ globs.
 A warning will be issued for refs that do not exist,
 but a glob that does not match any refs is silently ignored.
 +
-This setting can be disabled by the `--no-notes` option to the 'git
-log' family of commands, or by the `--notes=<ref>` option accepted by
+This setting can be disabled by the `--no-notes` option to the `git
+log` family of commands, or by the `--notes=<ref>` option accepted by
 those commands.
 +
-The effective value of "core.notesRef" (possibly overridden by
-GIT_NOTES_REF) is also implicitly added to the list of refs to be
+The effective value of `core.notesRef` (possibly overridden by
+`GIT_NOTES_REF`) is also implicitly added to the list of refs to be
 displayed.
 
-notes.rewrite.<command>::
-	When rewriting commits with <command> (currently `amend` or
+`notes.rewrite.<command>`::
+	When rewriting commits with _<command>_ (currently `amend` or
 	`rebase`), if this variable is `false`, git will not copy
 	notes from the original to the rewritten commit.  Defaults to
-	`true`.  See also "`notes.rewriteRef`" below.
+	`true`.  See also `notes.rewriteRef` below.
 +
 This setting can be overridden with the `GIT_NOTES_REWRITE_REF`
 environment variable, which must be a colon separated list of refs or
 globs.
 
-notes.rewriteMode::
+`notes.rewriteMode`::
 	When copying notes during a rewrite (see the
-	"notes.rewrite.<command>" option), determines what to do if
+	`notes.rewrite.<command>` option), determines what to do if
 	the target commit already has a note.  Must be one of
 	`overwrite`, `concatenate`, `cat_sort_uniq`, or `ignore`.
 	Defaults to `concatenate`.
 +
 This setting can be overridden with the `GIT_NOTES_REWRITE_MODE`
 environment variable.
 
-notes.rewriteRef::
+`notes.rewriteRef`::
 	When copying notes during a rewrite, specifies the (fully
 	qualified) ref whose notes should be copied.  May be a glob,
 	in which case notes in all matching refs will be copied.  You