Installation.md

@@ -43,7 +43,11 @@ Last, activate the shakemap virtual environment
 ```
 
 # Optional Installations
-The above instructions will install the minimum libraries required to run ShakeMap. For developers or system administrators, there are a number of additional packages that are useful for checking syntax, debugging, and building documentation. So we recommend the following optional installations:
+The above instructions will install the minimum libraries required to run ShakeMap. For developers or system administrators, there are a number of additional packages that are useful for checking syntax, debugging, and building documentation. To install the optional software you will first want to execute the following command:
+```
+conda config --append channels conda-forge
+```
+We recommend the following optional installations:
 ```
 conda install ipython \
               autopep8 \