[FR] Add an option to specify the folders in which a snippets functions

[proItheus]

I think it's good to have the ability to restrict a snippet to only expand in certain folders . This is useful in use cases like having several folders for different subjects (math, physics etc), thus need different set of snippets .

One possible approach to implememt this is to add a (optional) field in each snippet's definition like

path: [ "path/one", "path/two" ] 

Besides, it will be even better if we'll have some kind of glob support.

Thanks for you great work! : )

[artisticat1]

Do you have many snippets for different subjects that conflict with each other often? This would be a low-priority feature for me, but you're welcome to implement this and submit a PR!