README: Update project documentation

[osrsbox]

The README.md file has documentation needs various updates for the number of changes to the project recently, this includes:

• Restructure readme
  • Project quickstart with more information on new API
  • Database contents should also include prayer data
  • Database availability section with Python package, Restful API, reposiroty (remove static JSON API)
• Add install pip to python package section
• Add python object example output to the documentation, similar to how there are JSON examples
• Schema
  • Updated to the new Cerberus implementation
  • Link to the new schema repository where the schemas are now hosted