[docs] remove references to the wiki [skip CI]

Author: jcb91

README.md

@@ -57,12 +57,12 @@ Most also have a markdown readme file for documentation.
 The `jupyter_nbextensions_configurator` server extension shows an nbextensions
 tab on the main notebook dashboard (file tree page) from which you can see each
 nbextension's markdown readme, and configure its options.
-To view documentation without installing, you can browse the nbextensions
+To view documentation without installing, you can check the list at
+[jupyter-contrib-nbextensions.readthedocs.io/en/latest/nbextensions.html](http://jupyter-contrib-nbextensions.readthedocs.io/en/latest/nbextensions.html),
+or browse the nbextensions
 directory to read markdown readmes on github at
 [github.com/ipython-contrib/jupyter_contrib_nbextensions/tree/master/src/jupyter_contrib_nbextensions/nbextensions](https://github.com/ipython-contrib/jupyter_contrib_nbextensions/tree/master/src/jupyter_contrib_nbextensions/nbextensions).
 
-For older releases (2.x and 3.x), look at the [Wiki](https://github.com/ipython-contrib/jupyter_contrib_nbextensions/wiki)
-
 Some extensions are not documented. We encourage you to add documentation for them.
 
 
@@ -222,8 +222,6 @@ which will
 For complex or customized installation scenarios, please look at the
 documentation for installing notebook extensions, server extensions, nbconvert
 pre/postprocessors and templates on the [Jupyter homepage](https://jupyter.org).
-More information can also be found in the
-[Wiki](https://github.com/ipython-contrib/jupyter_contrib_nbextensions/wiki).
 
 See also [installing Jupyter](https://jupyter.readthedocs.io/en/latest/install.html)
 

docs/source/install.md

@@ -154,7 +154,5 @@ which will
 For complex or customized installation scenarios, please look at the
 documentation for installing notebook extensions, server extensions, nbconvert
 pre/postprocessors and templates on the [Jupyter homepage](https://jupyter.org).
-More information can also be found in the
-[Wiki](https://github.com/ipython-contrib/jupyter_contrib_nbextensions/wiki).
 
 See also [installing Jupyter](https://jupyter.readthedocs.io/en/latest/install.html)

src/jupyter_contrib_nbextensions/nbextensions/exercise/readme.md

@@ -24,7 +24,7 @@ The extensions provide
 - a cell widget -- A plus/minus button in `exercise` and a sliding checkbox in `exercise2`.
 
 The menubar button is devoted to the creation or removing of the solution. The solution consists in several consecutive cells that can be selected either by multicell selection (*Shift-J* (select next) or *Shift-K* (select previous) keyboard shortcuts --
-*Shift-up* and *Shift-down* will probably work in a near future) or using the [rubberband extension](https://github.com/ipython-contrib/jupyter_contrib_nbextensions/wiki/Rubberband).
+*Shift-up* and *Shift-down* will probably work in a near future) or using the rubberband extension.
 
 **Creating a solution **
 Several cells being selected, pressing the menubar button adds a `cell widget` and hides the cells excepted the first one which serves as a heading cell. *Do not forget to keep the Shift key pressed down while clicking on the menu button

src/jupyter_contrib_nbextensions/nbextensions/exercise2/readme.md

@@ -22,8 +22,7 @@ The example below demonstrates some of the features of the exercise extensions.
 - a cell widget -- A plus/minus button in `exercise` and a sliding checkbox in `exercise2`.
 
 The menubar button is devoted to the creation or removing of the solution. The solution consists in several consecutive cells that can be selected either by multicell selection (*Shift-J* (select next) or *Shift-K* (select previous) keyboard shortcuts --
-*Shift-up* and *Shift-down* will probably work in a near future) or using the
-[rubberband extension](https://github.com/ipython-contrib/jupyter_contrib_nbextensions/wiki/Rubberband).
+*Shift-up* and *Shift-down* will probably work in a near future) or using the rubberband extension.
 
 **Creating a solution **
 Several cells being selected, pressing the menubar button adds a `cell widget` and hides the cells excepted the first one which serves as a heading cell. *Do not forget to keep the Shift key pressed down while clicking on the menu button

src/jupyter_contrib_nbextensions/nbextensions/snippets_menu/readme.md

@@ -549,7 +549,7 @@ Comment out whatever you've got in `custom.js`, and add in the simple
 configuration from [the beginning](#installation).  If that doesn't
 work, try the following steps
 suggested
-[here](https://github.com/ipython-contrib/jupyter_contrib_nbextensions/wiki#troubleshooting):
+[here](http://jupyter-contrib-nbextensions.readthedocs.io/en/latest/troubleshooting.html):
 
   1. Clear your browser cache or start a private browser tab.
   2. Verify your `custom.js` is the one the notebook is seeing, by opening it