A collection of options that can be used to configure a model.
Options is the struct that represents a set of options for a large language model.
It provides methods for creating, adding, and retrieving options.
Loads options from environment variables.
Every option that can be easily understood from a string is avaliable the name
of the option will be in upper snake case, that means that the option Opt::ApiKey has the environment variable
LLM_CHAIN_API_KEY