Hasing and dehashing with the sha-256 algorithm.

Example usage:

• When hashing, entering a string will output its hash. (for example a will output ac231b3 9a23dc4d a786eff8 147c4e72 b9807785 afee48bb)
• When hashing, entering a hash of 64 characters without spaces will result in the secret. (for example ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb will give a)