Fun with SF Symbols

A simple demo app that demonstrates SF Symbol and Dark Mode usage.

There are a few views:

1. A simple "Hello World" label and icon showing basic SF Symbol use and using the system default colours for Dark Mode support.
2. A longer block of text showing centre aligning an SF Symbol with a block of text.
3. A slightly longer still block of text, but this time showing the new baselign aligning of text and symbols.
4. A colour label with a UIColor created in code.
5. Another colour label using a colour set in the asset catalog.
6. An image view with a blur effect applied, with the image having a light and dark appearance and the blur effect using the system material, also with a light and dark appearance.