If you were interested in knowing, "Is Github gone mad?" doesn't quite work in English as it's a mix of a past and present tense. For the past tense, you could

If you were interested in knowing, "Is Github gone mad?" doesn't quite work in English as it's a mix of a past and present tense. For the past tense, you could say "Has Github gone mad?". For the present tense, you could say "Is Github mad?". For what it's worth, North American English has moved on from using the word mad in this context, it sounds dated. That said, speak as you wish, English is different everywhere and there's no right or wrong when it comes to word-use IMO.