Hello,
So, in case you want to know where the MongoDB snippets were stored, either to edit them, to copy into your own MongoDB snippets section, and don’t want to waste 45 minutes hunting for them 
It’s only for windows sorry.
C:\Users<Username>\.vscode\extensions\mongodb.mongodb-vscode-0.5.0\snippets\stage-autocompleter.json
It’s one of those things I don’t do very often, but in this case I wanted to create a another version of the $lookup.
Cheers.