The way I would solve this (with my fairly rudimentary linux skillz) is to make an alias to the shell script.

First ensure the shell script is executable.

chmod u+x,g+x script.sh

Then, edit your .bashrc file like following:

cd

vi .bashrc

Add this towards the bottom. (I think you can also add this in a specific alias file, such as .bash_aliases, but I don't.)

alias commandtorun='/home/user/script.sh'

Here, commandtorun will be the command you type in to run the script, and '/home/user/script.sh' is the path to the script.

To save changes to your .bashrc in vi editor, :wq, which writes to file and quits.

Edit: You'll also need to re-source your .bashrc to use the changes in the current session. (Or just restart the session / close and reopen the terminal).

source ~/.bashrc

Good luck!