* [ios, macos] Optimized changelog for runtime styling
Changelog entries related to style JSON now lead off with the analogous portion of the runtime styling API.
* [ios, macos] Autolink cross-class property references in docs
jazzy can autolink `Class.property` references in documentation comments.
* [ios, macos] Removed extra blank lines
* [ios, macos] Corrected typo in MGLMultiPoint docs
* [ios, macos] Rewrote shape and feature docs
Rewrote documentation about MGLShape, its subclasses, and MGLFeature to emphasize runtime styling uses over annotation uses, associate each type with real-world concepts, cross-reference related style layer classes, and cross-reference related or easily confused shape classes. Links to the GeoJSON specification have been updated to RFC 7946.
* [ios, macos] Expanded style layer docs
With this change, documentation about style layer classes is nominally based on the documentation in the style specification. However, all the existing layer types’ documentation has been overridden to explain what the layer looks like, relate the layer to a real-world concept, and cross-reference related geometry classes. This change also corrects the description of MGLBackgroundStyleLayer, which erroneously stated that the identifier must be “background”, whereas that only happens to be true by default for Studio template styles.
* [ios, macos] Wrap style layer docs
* [ios, macos] Removed unused code
* [ios, macos] Corrected symbol references in docs
* [ios, macos] Corrected typo in abstract class exception
