General doc updates

Added missing doc, for example for serial tests, fixed 404 links,
spellings, formatting and etc

Change-Id: I07a8cf9508d3cba33bd04afdc301bb7145153d59
diff --git a/doc/source/tests/modules.rst b/doc/source/tests/modules.rst
index 026a7a5..697b011 100644
--- a/doc/source/tests/modules.rst
+++ b/doc/source/tests/modules.rst
@@ -19,3 +19,10 @@
    network/modules
    object_storage/modules
    volume/modules
+
+Serial Tests
+------------
+.. toctree::
+   :maxdepth: 2
+
+   serial_tests/modules