GitHub supported languages: https://github.com/github-linguist/linguist/blob/main/lib/linguist/languages.yml YQ CLI for extraction:
yq '[.[].extensions] | flatten | unique | .[] | split(".")[1] | [.] | unique | map("## " + . + "\n```" + . + "\nThis is sample text, interpunction: !? \nThisIsSampleText \nThis-Is-Sample-Text \nthis-is-sample-text \nBrackets [] {} () <>\nOther chars @ # $ % ^ & * - _ \|/ .\n```") | join("\n")' github-languages.yml
This is sample text, interpunction: !?
ThisIsSampleText