Add tox environment for spellcheck

Updates to how-to use documentation for linkcheck and spellcheck
Initial list of validword exceptions for immediate use of tox -espellcheck
Validword exceptions will be improved when DOC-262 is complete
Corrections of RST references based on recent Beijing contributions

Change-Id: Ic82de1088fd961c2ad91493e8736777aede1cdb1
Signed-off-by: Rich Bennett <rb2745@att.com>
Issue-ID: DOC-94
diff --git a/docs/release/releaserepos.rst b/docs/release/releaserepos.rst
index a69a0a5..74fb45d 100644
--- a/docs/release/releaserepos.rst
+++ b/docs/release/releaserepos.rst
@@ -79,7 +79,7 @@
    :maxdepth: 1
    :titlesonly:
 
-   dmaap/messagerouter/messageservice<../submodules/dmaap/messagerouter/messageservice.git/docs/release-notes.rst>
+   dmaap/messagerouter/messageservice<../submodules/dmaap/messagerouter/messageservice.git/docs/release-notes/release-notes.rst>
 
 External API / NBI
 ------