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

Converts ARM the text files to ReST, preparing them to be an
architecture book.

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>
Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
diff --git a/Documentation/arm/stm32/stm32h743-overview.rst b/Documentation/arm/stm32/stm32h743-overview.rst
index c525835..4e15f1a 100644
--- a/Documentation/arm/stm32/stm32h743-overview.rst
+++ b/Documentation/arm/stm32/stm32h743-overview.rst
@@ -1,5 +1,4 @@
-:orphan:
-
+==================
 STM32H743 Overview
 ==================
 
@@ -31,6 +30,4 @@
 
 .. _STM32H743: http://www.st.com/en/microcontrollers/stm32h7x3.html?querycriteria=productId=LN2033
 
-:Authors:
-
-Alexandre Torgue <alexandre.torgue@st.com>
+:Authors: Alexandre Torgue <alexandre.torgue@st.com>