Added example for connecting to unix socket

[cebe]

I was searching for a way to connect to redis via unix socket and I found it a bit too hard to find, so I added this here.

[clue]

Good catch, thank you for this contribution!

The code LGTM, but it makes me wonder if it makes more sense to just integrate this into this library. I was actually planning to integrate this somewhat similar to clue/reactphp-socks#69 and possibly use the redis+unix:// URI scheme here.

What do you think about this? 👍

[cebe]

of course it would make sense to add direct support for it but there are a few things that are unclear about how to handle it:

1. as you said, the scheme. redis+unix:// would be an option, I assume there is no standard for this?
   Also is the redis part needed? would unix:// be sufficient?
2. how to specify the database? redis+unix:///var/run/redis/redis.sock?db=2 would probably work, redis+unix:///var/run/redis/redis.sock/2 not so much as it is indistinguishable from a path.
3. specifying auth on a socket is pointless so its fine to skip that option imo.

[cebe]

Btw, I really like how much documentation is added for all the react libraries, thanks for that! :)

[clue]

Thank you for sparking this discussion and for your positive feedback, this has just been resolved via #70!