implement placement example with tabs

Rearrange DOM so that the FAQ answers share the same space as the code
example. Switch custom JS to use built-in Bootstrap tabs.
remove function to check if hash is provided
add styles for selected tab
implement script sample with tabs

also remove CSS and JS to handle custom hide/show of divs
remove placement tips to fit content inside box
refactor code examples under an info-item div

keeps markup consistent with all other into-items
tweak CSS to better fit answers into info-box
remove details on script customization