Better search for API Content Text

[gtalarico]

Ctrl+F :search doesn't work well sometimes because browser search will pick up text on the tree namespace navigation. Since it's not possible to limit browser scope for searching, the only solution is to implement a custom search:

1. Search box for text body search. possibly:
   https://jsfiddle.net/julmot/973gdh8g/

PS:
2. Tree menu search and filter, using fancytree or something like this:
https://jsfiddle.net/julmot/bs69vcqL/

PS 2:
a temporary workaround is to collapse navigation tree