Modularize and change format of quickhits.txt

**Describe the feature request**:
Similar to how `Discovery/Web-Content/combined_words.txt` and `Discovery/Web-Content/combined_directories` are composed of several other wordlists, it would be beneficial to modularize the quickhits.txt wordlist so it can contain automatically-updating components.

Using a different wordlist format should also be considered so that when the wordlist is used, it's easier to trace back which web service the matched URL path corresponds to.

**Next steps**:
Proposals for what that new format should look like are welcome.