Add a bash script (directory) to your terminal PATH

Edit the ~/.bashrc file to export the PATH with the directory containing your script(s). This will modify every terminal you open with the new path, exposing sripts in the directory you added.
We'll add a line to your .bashrc that exports your script directory to the path. Something like:

export PATH="~/your/path/to/bash_scripts/:$PATH"    

WARNING: :$PATH at the end is very important. Without it, you won't have access to the built-in scripts. If that happens, just navigate to your current user's home directory in the file manager, show hidden files, and edit .bashrc by hand.

Append to ~/.bashrc with echo

Edit the APPEND_PATH below (just click & type), then copy (ctrl+a, ctrl+c) & paste (ctrl+shift+V) into your terminal & enter

APPEND_PATH="~/your/path/to/bash_scripts/" # Because variables are cool    
echo "export PATH=\"${APPEND_PATH}:\$PATH\"" >> ~/.bashrc    
tail -n 2 ~/.bashrc # print the last two lines to verify it was added successfully    
# If it's wrong, delete the last line & tail again, with:    
# sed '$d' ~/.bashrc > ~/.bashrc.tmp && mv ~/.bashrc.tmp ~/.bashrc;  tail -n 2 ~/.bashrc;    

Or Use nano... so many keystrokes

nano ~/.bashrc    
# arrow key down to the bottom    
# type     
export PATH="~/your/path/to/bash_scripts/:$PATH"    
# Press ctrl+X    
# press 'Y' to save (or 'N' to cancel)    
# Press Enter (saves to same file name)