fixup comments, add verbatim tags

Author: joshgoebel

src/languages/yaml.js

@@ -86,11 +86,16 @@ export default function(hljs) {
         className: 'type',
         begin: '!\\w+!' + URI_CHARACTERS,
       },
-      { // local tags
+      // https://yaml.org/spec/1.2/spec.html#id2784064
+      { // verbatim tags
+        className: 'type',
+        begin: '!<' + URI_CHARACTERS + ">",
+      },
+      { // primary tags
         className: 'type',
         begin: '!' + URI_CHARACTERS,
       },
-      { // data type
+      { // secondary tags
         className: 'type',
         begin: '!!' + URI_CHARACTERS,
       },

test/markup/yaml/tag.expect.txt

@@ -7,3 +7,6 @@
 <span class="hljs-attr">key:</span> <span class="hljs-type">!foo2.bar</span> <span class="hljs-string">test</span>
 <span class="hljs-attr">key:</span> <span class="hljs-type">!(foo.bar?):tag</span> <span class="hljs-string">test</span>
 <span class="hljs-attr">key:</span> <span class="hljs-type">!named!tag</span> <span class="hljs-string">test</span>
+
+<span class="hljs-string">---</span> <span class="hljs-type">!&lt;tag:clarkevans.com,2002:invoice&gt;</span>
+<span class="hljs-attr">invoice:</span> <span class="hljs-number">34843</span>

test/markup/yaml/tag.txt

@@ -7,3 +7,6 @@ key: !!python/name:module.name test
 key: !foo2.bar test
 key: !(foo.bar?):tag test
 key: !named!tag test
+
+--- !<tag:clarkevans.com,2002:invoice>
+invoice: 34843