Option to create new stashed file

[shitchell]

After #182 is implemented, it would be nice to have the option to create a new file from within glow. On the main page, when viewing stashed files, type 'n' to create and begin editing a new file that will be added to the user's stash.

Proposed flow

1. At the main page, user types 'n'
2. The cursor is moved to the top of the page
3. A new entry is added to the list of stashed files
4. The user is prompted to enter a memo for the new entry (just like editing the memo for a normal file)

Memo: New File
Just now

5. After the user hits enter, a temporary file is created locally and opened with the editor
6. Once the editor exits, the temporary file is stashed with the given memo and deleted locally

At present, I have to create a new file, edit it, stash it, and then delete it. This enhancement would make glow pretty much a standalone (ignoring the fact that you need an external editor) tool to access, edit, and create files across devices.

[kjhughes097]

+1 for adding n to create a new file