docs: timers: convert docs to ReST and rename to *.rst

The conversion here is really trivial: just a bunch of title
markups and very few puntual changes is enough to make it to
be parsed by Sphinx and generate a nice html.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 342c7c7..a6d4368 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -5712,7 +5712,7 @@
 			# ignore udelay's < 10, however
 			if (! ($delay < 10) ) {
 				CHK("USLEEP_RANGE",
-				    "usleep_range is preferred over udelay; see Documentation/timers/timers-howto.txt\n" . $herecurr);
+				    "usleep_range is preferred over udelay; see Documentation/timers/timers-howto.rst\n" . $herecurr);
 			}
 			if ($delay > 2000) {
 				WARN("LONG_UDELAY",
@@ -5724,7 +5724,7 @@
 		if ($line =~ /\bmsleep\s*\((\d+)\);/) {
 			if ($1 < 20) {
 				WARN("MSLEEP",
-				     "msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt\n" . $herecurr);
+				     "msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.rst\n" . $herecurr);
 			}
 		}
 
@@ -6115,11 +6115,11 @@
 			my $max = $7;
 			if ($min eq $max) {
 				WARN("USLEEP_RANGE",
-				     "usleep_range should not use min == max args; see Documentation/timers/timers-howto.txt\n" . "$here\n$stat\n");
+				     "usleep_range should not use min == max args; see Documentation/timers/timers-howto.rst\n" . "$here\n$stat\n");
 			} elsif ($min =~ /^\d+$/ && $max =~ /^\d+$/ &&
 				 $min > $max) {
 				WARN("USLEEP_RANGE",
-				     "usleep_range args reversed, use min then max; see Documentation/timers/timers-howto.txt\n" . "$here\n$stat\n");
+				     "usleep_range args reversed, use min then max; see Documentation/timers/timers-howto.rst\n" . "$here\n$stat\n");
 			}
 		}