Simple extended JSON parser

This is a simple library open-source code for extended-JSON parsing. It understands (and emits) JSON containing Infinity and NaN numbers as unquoted tokens (an extension shared by Python's json library, among others) and it only decodes simply typed values. It (currently) does not know how to decode JSON into structs and their fields, but rather all JSON {objects} become map[string]any, all JSON [arrays] become []any, and all JSON values are represented within any values. (any in golang is synonymous with and shorthand for interface{}, a dynamically typed value type with no constraints and no guaranteed interface.)