Correct the published metadata

Adds library_name to the model card, and pipeline_tag where it was missing.
Brings the config and card licenses into agreement, and repairs the variant
declarations that did not match the files actually published here.

README.md

@@ -1,6 +1,7 @@
 ---
 license: apache-2.0
 pipeline_tag: automatic-speech-recognition
+library_name: executorch
 ---
 
 # Introduction

mlx/config.json

@@ -6,7 +6,7 @@
     "speech-to-text"
   ],
   "backend": "mlx",
-  "license": "mit",
+  "license": "apache-2.0",
   "tokenizer": "../tokenizer.json",
   "variants": [
     {
@@ -76,7 +76,7 @@
       "file": "whisper_base_mlx_int8.pte",
       "precision": "int8",
       "quantized": true,
-      "default": false,
+      "default": true,
       "methods": {
         "encode": {
           "inputs": [