quic: work more on api cleanups, start docs

Author: jasnell

doc/api/index.md

@@ -50,6 +50,7 @@
 * [Process](process.md)
 * [Punycode](punycode.md)
 * [Query strings](querystring.md)
+* [QUIC](quic.md)
 * [Readline](readline.md)
 * [REPL](repl.md)
 * [Report](report.md)