Add bittensor.timelock module description

[basfroman]

In addition to the basic usage, the user can use the logic to encrypt and decrypt custom objects. The description of the process is added to the module.

import pickle
from dataclasses import dataclass

from bittensor import timelock


@dataclass
class Person:
    name: str
    age: int

# get instance of your data
x_person = Person("X Lynch", 123)

# get bytes of your instance
byte_data = pickle.dumps(x_person)

# get TLE encoded bytes
encrypted, reveal_round = timelock.encrypt(byte_data, 1)

# wait when reveal round appears in Drand QuickNet and get decrypted data
decrypted = timelock.wait_reveal_and_decrypt(encrypted_data=encrypted)

# convert bytes into your instance back
x_person_2 = pickle.loads(decrypted)

# make sure initial and decoded instances are the same
assert x_person == x_person_2