Shortcuts update part 3: Added open new note intent and handler

[charliescheer]

Fix

First shortcut to reimplement with siri kit is open new note intent. This shortcut simply opens Simplenote and then creates a new note and opens that in the editor. It doesn't take any parameters or have any actions, so is fairly simple.

Test

1. Launch the app
2. go to the Shortcut app, create a new shortcut, add action, find Simplenote and select Open New Note.
3. Run the shortcut and confirm the app opens and creates a new note

Review

(Required) Add instructions for reviewers. For example:

Only one developer is required to review these changes, but anyone can perform the review.

Release

These changes do not require release notes.

[jleandroperez]

✅ Verified that the new Open new Note intent works as expected

[wpmobilebot]

You can test the changes in simplenote-ios from this Pull Request by:

• Clicking here or scanning the QR code below to access App Center
• Then installing the build number pr1580-efcd128-018f53e2-12b1-4a56-8a85-4ec422a2de34 on your iPhone

If you need access to App Center, please ask a maintainer to add you.