Fixed typos on docs/*

[caio]

Hey there,

I've just read through your docs. Thanks a lot for the guide, it's been really helpful as I begin my JavaScript unraveling.

While reading, I noticed a typo on the "Arrays" docs and, since you fellas have open sourced it, here are my "thank you very much" act :)

Best,

Caio Romão

[caio]

I've also noticed some free usage of ECMAScript and EcmaScript but didn't touch it since this might bow down to taste. Apparently the former is the correct casing, but the most important thing (IMO) is to keep the usage uniform. What do you think?

[BonsaiDen]

Thanks for the fixes. Yes I also think that the former version is the correct one, I'm going to fix it :)

[BonsaiDen]

Merges are done, added a contributors list in the intro section, currently listing only you but I hope the list grows at some point :)

[caio]

Wow, great response time! Keep up the docs quality and great contributors will surely appear :)