[model] Replace obj with gltf (Fixes #64)

model/README.md

@@ -83,13 +83,13 @@ resource in different formats to be specified.
 This is an example showing how a
 [USDZ](https://graphics.pixar.com/usd/docs/Usdz-File-Format-Specification.html)
 file may be shown in an area measuring 400px by 300px, with a fallback
-to a [obj](https://en.wikipedia.org/wiki/Wavefront_.obj_file)
+to a [glTF](https://www.khronos.org/gltf/)
 file.
 
 ```html
 <model style="width: 400px; height: 300px">
     <source src="assets/example.usdz" type="model/vnd.usd+zip">
-    <source src="assets/example.obj" type="model/obj">
+    <source src="assets/example.gltf" type="model/gltf+json">
 </model>
 ```
 
@@ -103,7 +103,7 @@ The previous example can be augmented to allow interaction provided by the brows
 ```html
 <model style="width: 400px; height: 300px" interactive>
     <source src="assets/example.usdz" type="model/vnd.usd+zip">
-    <source src="assets/example.obj" type="model/obj">
+    <source src="assets/example.gltf" type="model/gltf+json">
 </model>
 ```
 
@@ -116,7 +116,7 @@ The original example can be augmented to allow for such animations:
 ```html
 <model style="width: 400px; height: 300px" autoplay>
     <source src="assets/example.usdz" type="model/vnd.usd+zip">
-    <source src="assets/example.obj" type="model/obj">
+    <source src="assets/example.gltf" type="model/gltf+json">
 </model>
 ```
 
@@ -129,7 +129,7 @@ As such, the original example can be augmented to allow for both animations and
 ```html
 <model style="width: 400px; height: 300px" autoplay interactive>
     <source src="assets/example.usdz" type="model/vnd.usd+zip">
-    <source src="assets/example.obj" type="model/obj">
+    <source src="assets/example.gltf" type="model/gltf+json">
 </model>
 ```