Initial version of unit testing documentation

This commit includes the 'User guide' and 'Implementing tests' sections
for helping people building, running and writing unit tests. A more
detailed version of documentation is available under the 'Component
user manuals section'.

Change-Id: I67e93ac805d1f4e7727964f3d95a70436ae34733
Signed-off-by: Imre Kis <imre.kis@arm.com>
diff --git a/docs/components/index.rst b/docs/components/index.rst
new file mode 100644
index 0000000..3e8a68b
--- /dev/null
+++ b/docs/components/index.rst
@@ -0,0 +1,14 @@
+Component user manuals
+======================
+
+.. toctree::
+	cpputest
+	cppumock
+	c_picker
+	build_system
+	code_coverage
+
+
+--------------
+
+*Copyright (c) 2019, Arm Limited. All rights reserved.*