JSON parse and better docs

• Adds functionality to parse json data with ijson.Parse() and ijson.ParseBytes() functions.
• Adds GH Actions integration to check build and test.
• Updates Readme to be more readable by explaining all possible operations over JSON data.

Base release (beta)

This is the base release with the following features.

• Easy to use path syntax to access nested interface data.
• Query, Set, Delete operations on interface data.
• Support for "." separated path to access values.
• Chainable operations to provide flexibility to perform multiple operations in a single line. See ijson.go for details.