Cleanup

- Use doc8 to check rst files
- Add spellcheck and VOLTHA-specific dictionary, fix spelling
- Other formatting and content fixes

Change-Id: I1eea3ab6eba4ec34af0788a681f1e8cd258ea988
diff --git a/overview/development_loop.rst b/overview/development_loop.rst
index 581a1e7..34ab2d7 100644
--- a/overview/development_loop.rst
+++ b/overview/development_loop.rst
@@ -50,4 +50,5 @@
 
 .. code:: bash
 
-    $ DEPLOY_K8S=no ./voltha down && DEPLOY_K8S=no EXTRA_HELM_FLAGS="-f dev-values.yaml" ./voltha up
\ No newline at end of file
+    $ DEPLOY_K8S=no ./voltha down && DEPLOY_K8S=no EXTRA_HELM_FLAGS="-f dev-values.yaml" ./voltha up
+