fix getFileExtension missing numeric extensions (e.g. mp4)

Jacky Zhao

2023-08-09 e4950e06a15e34134b9feb064749748080bd59a1

 .prettierrc

@@ -2,5 +2,6 @@
  "printWidth": 100,
  "quoteProps": "as-needed",
  "trailingComma": "all",
  "tabWidth": 2
  "tabWidth": 2,
  "semi": false
}