Doc: forbid JSDoc warnings & work around tag checker

The Popups' JSDocs currently generate without any warnings. Let's keep
it that way for as long as we can by enabling pedantic mode which causes
a failing exit status when warnings are emitted. This behavior can be
verified by adding adding `/** @ignore foo */`.

The JSDoc tag checker should leverage the default enabled dictionaries
but that doesn't seem to be happening[0]. For the time being, allow
unknown tags so that the full range is supported, including @template,
which are very useful for type checking. Minerva already allows unknown
tags.

Lastly, change spaces to tabs since that's what this codebase uses.

[0] https://github.com/jsdoc3/jsdoc/issues/1542

Change-Id: I0aef9f7a6ca4af28d104628cda7763ec70110413

jsdoc.json

@@ -1,17 +1,18 @@
 {
-  "source": {
-    "include": [
-      "src/"
-    ]
-  },
-  "opts": {
-    "destination": "doc/autogenerated/",
-    "recurse": true
-  },
-  "plugins": [
-    "plugins/markdown"
-  ],
-  "tags": {
-    "allowUnknownTags": false
-  }
+	"source": {
+		"include": [
+			"src/"
+		]
+	},
+	"opts": {
+		"destination": "doc/autogenerated/",
+		"pedantic": true,
+		"recurse": true
+	},
+	"plugins": [
+		"plugins/markdown"
+	],
+	"tags": {
+		"allowUnknownTags": true
+	}
 }