fix: move demo.js to the docs folder

[XhmikosR]

npm run lint will complain, though, so alternatively the file could be moved to a new folder or the docs folder.

Note that currently the file is linked in README.md from the root folder.

[wraithgar]

Yes it is going to have to move to a docs folder, and the readme should be fixed too.

[wraithgar]

This will also need to be a fix since it does affect the published module.

[XhmikosR]

Done:

C:\Users\xmr\Desktop\gauge>npm i --production

added 11 packages, and audited 12 packages in 11s

found 0 vulnerabilities

C:\Users\xmr\Desktop\gauge>node docs\demo.js
Demoing output for ASCII
Demoing output for colorASCII
Demoing output for brailleSpinner
Demoing output for colorBrailleSpinner