doc,tool: add tls.TLSSocket to typeMap

We use tls.TLSSocket type in tls.md, so that needs to be added to doctool's typeMap

PR-URL: https://github.com/nodejs/node/pull/8742
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

tools/doc/type-parser.js

@@ -29,6 +29,7 @@ const typeMap = {
   'cluster.Worker': 'cluster.html#cluster_class_worker',
   'dgram.Socket': 'dgram.html#dgram_class_dgram_socket',
   'net.Socket': 'net.html#net_class_net_socket',
+  'tls.TLSSocket': 'tls.html#tls_class_tls_tlssocket',
   'EventEmitter': 'events.html#events_class_eventemitter',
   'Timer': 'timers.html#timers_timers'
 };