Add FAQ section in the docs #809

A few questions keep popping up from time to time, most of the time related to snabbdom usage. Two current examples are #808 and #807 .
I think we should add a section in the docs where we can provide solutions for those common problems.
Problems to include:

• hooking into the element creation/update/deletion (Best integration strategy with CSS lib? #807)
• Using props for attrs that change (except for svg) (Inconsistencies in form input element DOM updates  #808)
• Execute code when DOM is loaded (Stackoverflow)
• Lenses with makeCollection (Stackoverflow)