docs: convert README, CODING_STYLE and HACKING to RST syntax

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d24c944..aa9a354 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -461,7 +461,7 @@
 
 	my @tree_check = (
 		"COPYING", "MAINTAINERS", "Makefile",
-		"README", "docs", "VERSION",
+		"README.rst", "docs", "VERSION",
 		"vl.c"
 	);