Add this to the end of LocalSettings.php file:

Permit upload of these files

$wgFileExtensions = array( 'py', 'sh', 'png', 'gif', 'jpg', 'jpeg', 'doc',
  'xls', 'mpp', 'pdf', 'ppt', 'tiff', 'bmp', 'docx', 'xlsx',
  'pptx', 'ps', 'odt', 'ods', 'odp', 'odg'
);

Dangerous! Don't enable on public sites. We are enabling it here to allow upload of bash scripts.

$wgVerifyMimeType = false;

• MediaWiki inside Docker container
• Lock down Mediawiki

• https://stackoverflow.com/questions/21883005/upload-any-file-type-to-mediawiki
• https://www.mediawiki.org/w/index.php?title=Manual:$wgMimeTypeBlacklist&oldid=3891362