[yt-dev] Issue #1106: [experimental] demonstrate how to use the VR annotations in the docs (yt_analysis/yt)

New issue 1106: [experimental] demonstrate how to use the VR annotations in the docs https://bitbucket.org/yt_analysis/yt/issues/1106/experimental-demonstrate-ho... Cameron Hummels: VR annotations (e.g. annotate_grids()) don't get much play in the cookbook or in the narrative docs to show how to use them.