Pre-release 1.0.0 beta

[rolfsimoes]

This version comes with support of reading static catalogues:

• read_stac(): read any STAC document from an URL (e.g. Catalog, Collection, Items, or Item);
• links(): extract and filter links from a STAC document;
• link_open(): open the document referenced by the provided link;
• read_items(): read items listed in links section of the provided Collection document;
• read_collections(): read collections listed in links section of the provided Catalog document;

It also provide new functions to facilitate work with items:

• items_as_sf() / items_as_sfc(): convert items into sf objects
• items_intersects(): is a helper function to test what items intersect some given geometry.