Clean up the README
Clean up the README

Update the requirements, and clean up the text.

Distrotech/json-glib,GNOME/json-glib,frida/json-glib,GNOME/json-glib,Distrotech/json-glib,ebassi/json-glib,Distrotech/json-glib,ebassi/json-glib,ebassi/json-glib,frida/json-glib