Allow Selecting multiple recipe folders

[thatkookooguy]

Is your feature request related to a problem? Please describe.
I want to have at least 2 folders for recipes:

• my private recipes
• my family recipes
• friends recipes?
• dog recipes?

When creating or importing a new recipe, cookbook should ask which folder to put it in or the user can set a default save folder

This will also help issues like #120 so people can have their own recipe folder and a shared recipes folder.

Describe the solution you'd like
admin settings: set a default path for any shared recipes folders for new users. maybe set for each folder if users can write new recipes into it or not.
users: can set multiple folders as recipes folders. it will show as different categories in the cookbook UI. they can also move recipes between categories (which will move them between folders).

Describe alternatives you've considered