Fix sphinx warnings with recommonmark 0.5

docs/contributing/features.md

@@ -7,7 +7,7 @@ Thank you for contributing to the Jupyter Docker Stacks! We review pull requests
 Please follow the process below to suggest a new feature for inclusion in one of the core stacks:
 
 1. [Open a GitHub issue](https://github.com/jupyter/docker-stacks/issues) describing the feature you'd like to contribute.
-2. Discuss with the maintainers whether the addition makes sense in [one of the core stacks](../using/selecting.html#Core-Stacks), as a [recipe in the documentation](recipes.html), as a [community stack](stacks.html), or as something else entirely.
+2. Discuss with the maintainers whether the addition makes sense in [one of the core stacks](../using/selecting.md#Core-Stacks), as a [recipe in the documentation](recipes.md), as a [community stack](stacks.md), or as something else entirely.
 
 ## Selection Criteria
 

docs/contributing/recipes.md

 # New Recipes
 
-We welcome contributions of [recipes](../using/recipes.html), short examples of using, configuring, or extending the Docker Stacks, for inclusion in the documentation site. Follow the process below to add a new recipe:
+We welcome contributions of [recipes](../using/recipes.md), short examples of using, configuring, or extending the Docker Stacks, for inclusion in the documentation site. Follow the process below to add a new recipe:
 
 1. Open the `docs/using/recipes.md` source file.
-2. Add a second-level Markdown heading naming your recipe at the bottom of the file (e.g., `## Add the RISE extension``)
+2. Add a second-level Markdown heading naming your recipe at the bottom of the file (e.g., `## Add the RISE extension`)
 3. Write the body of your recipe under the heading, including whatever command line, Dockerfile, links, etc. you need.
 4. [Submit a pull request](https://github.com/PointCloudLibrary/pcl/wiki/A-step-by-step-guide-on-preparing-and-submitting-a-pull-request) (PR) with your changes. Maintainers will respond and work with you to address any formatting or content issues.

docs/using/common.md

@@ -75,7 +75,7 @@ In either case, Jupyter Notebook expects the key and certificate to be a base64
 For additional information about using SSL, see the following:
 
 * The [docker-stacks/examples](https://github.com/jupyter/docker-stacks/tree/master/examples) for information about how to use [Let's Encrypt](https://letsencrypt.org/) certificates when you run these stacks on a publicly visible domain.
-* The [jupyter_notebook_config.py](jupyter_notebook_config.py) file for how this Docker image generates a self-signed certificate.
+* The [jupyter_notebook_config.py](https://github.com/jupyter/docker-stacks/blob/master/base-notebook/jupyter_notebook_config.py) file for how this Docker image generates a self-signed certificate.
 * The [Jupyter Notebook documentation](https://jupyter-notebook.readthedocs.io/en/latest/public_server.html#securing-a-notebook-server) for best practices about securing a public notebook server in general.
 
 ## Alternative Commands

docs/using/recipes.md

 # Contributed Recipes
 
-Users sometimes share interesting ways of using the Jupyter Docker Stacks. We encourage users to [contribute these recipes](../contributing/recipes.html) to the documentation in case they prove useful to other members of the community by submitting a pull request to `docs/using/recipes.md`. The sections below capture this knowledge.
+Users sometimes share interesting ways of using the Jupyter Docker Stacks. We encourage users to [contribute these recipes](../contributing/recipes.md) to the documentation in case they prove useful to other members of the community by submitting a pull request to `docs/using/recipes.md`. The sections below capture this knowledge.
 
 ## Using `pip install` or `conda install` in a Child Docker image
 

docs/using/selecting.md

@@ -21,7 +21,7 @@ The Jupyter team maintains a set of Docker image definitions in the [https://git
 | [Dockerfile commit history](https://github.com/jupyter/docker-stacks/commits/master/base-notebook/Dockerfile)
 | [Docker Hub image tags](https://hub.docker.com/r/jupyter/base-notebook/tags/)
 
-`jupyter/base-notebook` is a small image supporting the [options common across all core stacks](common.html). It is the basis for all other stacks.
+`jupyter/base-notebook` is a small image supporting the [options common across all core stacks](common.md). It is the basis for all other stacks.
 
 * Minimally-functional Jupyter Notebook server (e.g., no [pandoc](https://pandoc.org/) for saving notebooks as PDFs)
 * [Miniconda](https://conda.io/miniconda.html) Python 3.x in `/opt/conda`
@@ -148,4 +148,4 @@ The core stacks are just a tiny sample of what's possible when combining Jupyter
 
 * [education-notebook is a community Jupyter Docker Stack image](https://github.com/umsi-mads/education-notebook). The image includes nbgrader and RISE on top of the datascience-notebook image. Click here to launch it on [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/umsi-mads/education-notebook/master).
 
-See the [contributing guide](../contributing/stacks.html) for information about how to create your own Jupyter Docker Stack.
+See the [contributing guide](../contributing/stacks.md) for information about how to create your own Jupyter Docker Stack.