Lowercase ext before querying the mimedb on mimetypes module, change isMainModule to runnableExamples (#10644)
Lowercase ext before querying the mimedb on mimetypes module, change isMainModule to runnableExamples (#10644)


dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim,dom96/Nim