Merge pull request #365 from bgerrity/fix-config-docs-link

fix link to Jupyter common configuration docs

docs/source/config-options.md

@@ -1,6 +1,6 @@
 # Configuration options
 
-The kernel gateway adheres to the [Jupyter common configuration approach](https://jupyter.readthedocs.io/en/latest/projects/config.html). You can configure an instance of the kernel gateway using:
+The kernel gateway adheres to the [Jupyter common configuration approach](https://jupyter.readthedocs.io/en/latest/use/config.html). You can configure an instance of the kernel gateway using:
 
 1. A configuration file
 2. Command line parameters