Doc: Added M2R library dependency

Change-Id: I702a2afd911fec4743ca68e5db5170b071f60cec
Signed-off-by: Galanakis, Minos <minos.galanakis@arm.com>
diff --git a/readthedocs/requirements.txt b/readthedocs/requirements.txt
new file mode 100644
index 0000000..c58c8db
--- /dev/null
+++ b/readthedocs/requirements.txt
@@ -0,0 +1,8 @@
+# -*- coding: utf-8 -*-
+#-------------------------------------------------------------------------------
+# Copyright (c) 2019, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+#-------------------------------------------------------------------------------#
+m2r==0.2.1