Ability to download all of a skill's APL documents

[habuma]

Currently, the ASK toolkit extension supports downloading a skill's APL documents one at a time. It would be helpful if the download feature offered the ability to pull all APL documents at once.

Similarly, if #264 is implemented, the same option for APLA documents.

(Or, even better, an option from the editor to do the equivalent of ask smapi export-package directly into the project.)