I am trying to setup PyCharm to invoke a shell script, instead of python, as the run option. Is this possible? In the default options I only have Python, Python docs, and Python
If you want to see such a feature in PyCharm please vote on IDEA-112256 'Command Line' Run Configuration feature request.
Run/Debug Configurations section of Pycharm's online help lists all supported types of Run/Debug configurations and there's no support for shell scripts indeed. However, you might be able to add such support by installing a plugin. For example, if you are interested in bash scripts there's BashSupport plugin which adds support for running shell scripts in Run/Debug configuration.
From plugins' home page:
BashSupports can directly run scripts within IntelliJ. You can create a new run configuration for Bash scripts. Here you can set which interpreter is used to run it. Whenever a script is executed the output is logged. If Bash prints out syntax errors then the errorneous lines are clickable to jump to the location of the error.
For Windows there's CmdSupport plugin which provides an action to run .cmd scripts. It seems it does not support running such scripts as Run/Debug configuration however.
As a workaround you can use Python run/debug configuration, specifying some dummy (empty) Python file to run and use Before launch option specifying External tool and specify path to the script when adding/configuring this external tool. See In IntelliJ IDEA, how can I create a key binding that executes a shell script with the current file as a parameter? for details.
As PyCharm is based on IntelliJ's IDEA platform the question IntelliJ IDEA: Running a shell script as a Run/Debug Configuration is very related.
Speaking of run/debug configurations you might be interested in the plugin Run Configuration as Action which
(...) provides a way to use run configurations as buttons on toolbar. Or assign shortcuts to execute specific run configuration.