Register 12 new JSON filenames/extensions (#4053)

Added:
* .avsc
* .gltf
* .htmlhintrc
* .jscsrc
* .jslintrc
* .jsonl
* .tern-config
* .tern-project
* .tfstate
* .tfstate.backup
* .webapp
* .webmanifest

samples/JSON/filenames/.htmlhintrc

@@ -0,0 +1,25 @@
+{
+	"alt-require": true,
+	"attr-lowercase": true,
+	"attr-no-duplication": true,
+	"attr-unsafe-chars": true,
+	"attr-value-double-quotes": true,
+	"attr-value-not-empty": false,
+	"doctype-first": true,
+	"doctype-html5": true,
+	"head-script-disabled": false,
+	"href-abs-or-rel": false,
+	"id-class-ad-disabled": true,
+	"id-class-value": false,
+	"id-unique": true,
+	"inline-script-disabled": true,
+	"inline-style-disabled": true,
+	"space-tab-mixed-disabled": "space",
+	"spec-char-escape": true,
+	"src-not-empty": true,
+	"style-disabled": false,
+	"tag-pair": true,
+	"tag-self-close": false,
+	"tagname-lowercase": true,
+	"title-require": true
+}