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/index.rst b/doc/source/index.rst
index 2f29cf2..0340f8d 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -83,6 +83,7 @@
    :maxdepth: 2
 
    HACKING
+   serial_tests
    REVIEWING
    microversion_testing
    test_removal