Add canary version to AccessHandle prototype

Author: fivedots

AccessHandle.md

@@ -215,9 +215,9 @@ convenient, both from a specification and performance point of view.
 
 ## Trying It Out
 
-A prototype of access handles is available in Chrome Canary. To enable
-it, launch Chrome with the `--enable-features=FileSystemAccessAccessHandle`
-flag.
+A prototype of access handles is available in Chrome Canary (from at least
+version `94.0.4597.0`). To enable it, launch Chrome with the
+`--enable-features=FileSystemAccessAccessHandle` flag.
 
 We have also developed an Emscripten file system based on access handles.
 Instructions on how to use it can be found