Note Float16Array emulation path

Author: anssiko

index.bs

@@ -3154,7 +3154,7 @@ console.log('Output value: ' + result.outputs.output);
         <td>{{Float32Array}}
     <tr>
         <td>{{MLOperandType/float16}}
-        <td><p class="issue">TC39 <a href="https://tc39.es/proposal-float16array/">`Float16Array`</a> is work in progress. <a href="https://github.com/webmachinelearning/webnn/issues/373">[Issue webnn#373]</a></p>
+        <td><p class="issue">TC39 <a href="https://tc39.es/proposal-float16array/">`Float16Array`</a> is work in progress. Implementations can emulate this type by passing raw bits via {{Uint16Array}}. <a href="https://github.com/webmachinelearning/webnn/issues/373">[Issue webnn#373]</a></p>
     <tr>
         <td>{{MLOperandType/int32}}
         <td>{{Int32Array}}