Update the README to make use of the new configuration file.

[Dracovian]

The experimental branch code is using my SetFile (Settings File) file type while the master branch code is still using JSON as the config file type.

The following can be translated directly from the master branch configuration process and the experimental branch configuration process:

• The method of acquiring one's authorization token.
• The method of picking and choosing what to scrape by category.
• The method of acquiring guild/server and channel IDs.
• The method of acquiring DM channel IDs.

I'll have to go into greater detail as well because I can imagine some confusion will reside between those who are new to JSON and those who aren't familiar with SetFiles.