[Feature] - iOS 14 widgets showing today's schedule

[jevonmao]

Partially implemented in fadfbf8, but still needs more polishing in terms of functionality and UI design. Currently, there is 1 large family widget option that shows today's schedule in a block of text.

For v0.2.0 release:

• Small & Medium widgets (next period or time left in current period)
• More UI color options (configurable)
• Deep linking URL
• Placeholder/loading state widget