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

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: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

arch/m68k/q40/README

@@ -31,7 +31,7 @@ drivers used by the Q40, apart from the very obvious (console etc.):
 		char/joystick/*		# most of this should work, not
 				        # in default config.in
 	        block/q40ide.c		# startup for ide
-		      ide*		# see Documentation/ide/ide.txt
+		      ide*		# see Documentation/ide/ide.rst
 		      floppy.c		# normal PC driver, DMA emu in asm/floppy.h
 					# and arch/m68k/kernel/entry.S
 					# see drivers/block/README.fd