Redisearch 2.x support

[devinsburke]

Background: The only/best Redisearch library for golang (https://github.com/RediSearch/redisearch-go) uses Redigo as its base, and is primarily written for Redisearch 1.x. I don't know how familiar you all are with Redisearch 2.x, but it's so tightly integrated into Redis now that it doesn't make sense for the Redisearch library to be its own API (IMO).

I've forked go-redis/redis and am adding baseline Redisearch 2.x support, with TODOs for all commands and arguments that I don't perceive as minimum-viable product. I estimate that I'll be done with it in the next few days.

Will there be any strong resistance to adding non-core-redis module support to the mainline API?

Afterward, I will be skipping my 'TODO' Redisearch commands in favor of adding RedisJSON module support, which is also very tightly integrated into Redis.