title: RecyclerView with Alphabet Index
body: <p>I am attempting to build a RecyclerView list, with an alphabetical indexer down the right hand side. I have the list displaying perfectly and am able to scroll.</p>
  
  <p>I am wondering if someone could give me some guidance in building the alphabetical indexer. I believe I need to iterate through my list and determine the letters used (I can do this). Then build the list of letters (for the indexer) and then use scrollToPosition(int position) to move to the right item in the list when a letter is selected.</p>
  
  <p>The main issue that I can not work out is not building another list, it is rather the communication between the two lists. Any help would be greatly appreciated.</p>