following: https://craftinginterpreters.com/

Implemented a hashmap!

1. add support for lists (usage)
2. add static methods to classes using metaclasses (usage)
3. add getter methods to classes (usage)
4. add hash native function (usage)
5. support modulus % operator
6. allow for nested block comments: /* ... /* ... */ ... */
7. variables must be initialized before accessed (they don't default to nil)
8. disallow division by 0
9. when the left operand of + is a string, cast right operands into strings
10. add break statements (usage). didn't add continue, it's a little more troublesome since it requires desugaring the for loop and performing the increment when the loop hits a continue.