Redis constructor doesn't parse protocol from host if RedisOptions are passed

[Starttoaster]

This was perhaps just confusing to me from the documentation. But reading Alternatively, specify the connection through a rediss:// URL. from the readme, it seemed intuitive to me that I could declare a client like:

const redis = new Redis({
  host: "rediss://redis.my-service.com",
  port: 6379,
});

And the constructor would parse the protocol rediss:// out from the host string. That appears to not be the case, and only available if specified like:

const redis = new Redis("rediss://redis.my-service.com");

This is probably expected constructor behavior, but wasn't intuitive to me based on the documentation. I would suggest an action item of either:

1. Update the documentation to say something like Alternatively, specify the connection through a rediss:// URL if not passing RedisOptions.
2. Change the constructor to parse the protocol out from either mode. It seems like it would be a non-breaking change at least. And makes it less likely that some other dummy like me opens a similar Issue in the future :)
3. Do nothing, perhaps what I find unintuitive is common sense to everyone else. If this is the option chosen, feel free to close the Issue.

I believe the value in choosing 2 comes with deployment options. It makes it simpler to take pre-existing code that uses the RedisOptions struct (but omits the tls key), and upgrade it to use TLS connections if the proxy in front of your Redis server changes from a TLS-disabled configuration to a TLS-optional one. Say the host string in RedisOptions is set from an environment variable, a person deploying that code could simply change the relevant environment variable to include rediss://, rather than make a pull request to optionally specify tls: {} in their client configuration code.