tag implication / alias cloudy sky -> cloud

The tag cloudy_sky has about 60 posts in it, sometimes showing only a few clouds in the background, post #853745, post #146004. The tag cloud has about 12000 posts with many posts having full cloud coverage, post #886747, post #388397.

I suggest we alias cloudy_sky to cloud for consistency. If not, implicate.

ion288 said:
I suggest we alias cloudy_sky to cloud for consistency. If not, implicate.

I would suggest implicating it to both cloud and sky. That would be consistent with how night_sky and starry_sky are done now.