Add region and endpoint additional config to readme

[pointtoken]

Great library! It might be useful in the docs to show how to configure the library, as follows:

   const seasons = new Isotope<Season>({
    domain: "seasons",                     
    key: "id"                            
  }, { region 		: 'US-East',
  endpoint 	: 'https://sdb.amazonaws.com'} );

Without this additional config, I couldn't get things working...

[squidfunk]

Thanks for noting! Definitely needs to be in the docs 😄 The reason why it's not is that I still need to revisit the configuration design. I probably change it to a further key of the first parameter and maybe refactor the other options.