wip

[chriswhong]

This PR includes several updates to the storytelling template.

• mapboxgl is updated to 3.8.0
• intersection-observer is no longer required as a dependency
• index.html and config.js are moved to the root of the repo, allowing index.html to be run from the live-server extension in V.S. Code without difficulty.
• The inset map implementation was creating a second Mapbox GL JS instance, which would incur additional map loads. It has been removed and replace with the mapbox-gl-globe-minimap plugin, which renders an SVG minimap. Additional configuration for the globe minimap is added.
• README is updated to include tables for all configuration options for easier readability.
• Additional instructions have been added for how to run the storytelling app using the live-server extension in Visual Studio Code.

Updates are made to the default config.js file to get rid of placeholder text:

• The chapters are all titled with the cities they show, and images from wikimedia commons have been added to each chapter.
• The user only needs to add their access token and can explore the fully-functional storytelling map.