[docs] fix sphinx some warnings

docs/source/conf.py

@@ -78,6 +78,8 @@ pygments_style = 'sphinx'
 # Set standard backtick role
 default_role = 'code'
 
+suppress_warnings = ['image.nonlocal_uri']
+
 # -- Options for HTML output --------------------------------------------------
 
 if not on_rtd:  # only import and set the theme if we're building docs locally

src/jupyter_contrib_nbextensions/nbextensions/addbefore/readme.md

@@ -1,3 +1,6 @@
+Addbefore
+=========
+
 This extension adds a button to add a empty cell before the currently active cell.
 As was present in IPython 1.0.
 It is with a circled up arrow.

src/jupyter_contrib_nbextensions/nbextensions/toc2/README.md

@@ -57,7 +57,7 @@ This option requires the IPython kernel and is not present with other kernels.
 ## Testing 
 - At loading of the notebook, configuration and initial rendering of the table of contents were fired on the event "notebook_loaded.Notebook". It happens that the extension is sometimes loaded *after* this event. I now rely  on a direct rendering at load and on a combination of  "notebook_loaded.Notebook" and "kernel_ready.Kernel". 
 
-- This extension also includes a quick workaround as described in [#429](https://github.com/ipython-contrib/jupyter_contrib_nbextensions/issues/429)
+- This extension also includes a quick workaround as described in [#429](https://github.com/ipython-contrib/jupyter_contrib_nbextensions/pull/429)
 
 ## History