Create FAQ page

[ldcouto]

From overturetool/overture#414 ...

"We have to make a note or FAQ somewhere to assist the user in solving this. It is correct that this is a Java 8 installer problem which sucks in almost all possible ways. It doesn't install the stuff it should be removed more than it is asked for - not a great installer."

[peterwvj]

There's a FAQ section now. At the current time of writing it covers issues that Mac OSX users may experience. Although Java related issues, such as those described in overturetool/overture#414 seem to happen much less frequently now, we should at least consider adding that to the FAQ as well.