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

In order to prepare to add them to the Kernel API book,
convert the files to ReST format.

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>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/scheduler/text_files.rst b/Documentation/scheduler/text_files.rst
new file mode 100644
index 0000000..0bc5030
--- /dev/null
+++ b/Documentation/scheduler/text_files.rst
@@ -0,0 +1,5 @@
+Scheduler pelt c program
+------------------------
+
+.. literalinclude:: sched-pelt.c
+    :language: c