Updated index.html to not have any profanity

[chriscn]

Fixes #149
I have just finished the index.html english version. I love this guide and often use it but for teachers the profanity is stopping it from being used in the classroom. Someone should update in the other languages.

[msscsh]

I think you are right @chriscn. Here I found a tool that makes learning much easier and I use it to teach informally. I believe that for an institution it would be a problem.

I don't believe this word should be kept as it is preventing the tool from reaching new heights