docs: Added guide to create an iOS shortcut, which makes use of the recipe/create/image API via OpenAI

[joschkarick]

What this PR does / why we need it:

The current community guide for iOS shortcuts provides a shortcut, which makes use of Google AI Studio and OCR. With OpenAI-image-parsing available, it's easier to make use of the Mealie API. With the updated iOS shortcut I wanted to make use of only Mealie API, so no AI Studio API key is required. I only added a adjusted version of the iOS shortcut doc.

Which issue(s) this PR fixes:

None

Special notes for your reviewer:

I am not sure if I'm missing any features of the Google AI Studio version. If so, they are not documented on the doc page.

Testing

Work through the tutorial and test the following ways:

• Trigger from sharing menu for images
• Trigger from sharing menu for URLs
• Trigger shortcut and take image
• Trigger shortcut and import existing image
• Trigger shortcut and take image of URL

Each trigger should lead to a successfully created recipe in Mealie.