text to py file

I understand nothing about coding.
When some make a addon it is in text. how do I download it in a py file so I have the nice little pythons icon. Im tired of copy and past as I never learned how to change the file and never came across the instructions.
Thank you

Depending on the browser being used you can RMB on a link and File / Save As or equibalent.
If it opens in the browser you can use ‘File / Save Page As’ or equivalent
Or if you download a .txt file then just change the file extension to .py
It’s just a plain text file with a different file extension

starting from the page you linked (the script on github), you can just click on ‘BlenderAddons’ (this is displayed twice on the page; it doesn’t matter which one you click) - by doing this you go one level ‘up’ on the project site. From there just click the button shown on the right side, ‘download ZIP’, which will download a zipfile containing the folder ‘BlenderAddons-master’, containing the project files including ‘EdgeRoundifier.py’. Just extract to somewhere, done.

There is a button Raw on the GitHub pages - if you click this you can use File - Save Page As (using FF as a browser; IE should have something similar). Page will be saved as a python code with proper formatting and extension .py
If some addon consists of several files Github usually has a button Dowload Zip at the addon’s root folder. Most likely blender can use zip file directly if you point it using Install from File button in User preferences- Addons.

Thanks so much. I have looked for the answer so long. I did not ask because I knew it must be simple.