title: r what filename for saving gganimate file
body: <p>The following two lines of code, taken from this <a href="https://github.com/openmodelingfoundation/landuse/blob/master/R/importLUH2Data.R" rel="nofollow noreferrer">script</a>, do what I think they should; that is, use a previously generated ggplot file - gganim - create an animation in Rstudio's viewer (the first line) and save the last animation to the graphics directory on my mac (the second line). But my mac thinks this is a txt file. I've tried adding .mpeg, mp4, etc. to the file name without any success. Seems like one of this problems I'll do a Homer Simpson on after someone points out the solution.</p>
  
  <pre><code>gganimate::animate(gganim, nframes = length(yearsToDisplay), fps = 1, renderer = ffmpeg_renderer())
  gganimate::anim_save("animateOutput", animation = last_animation(), path = "graphics")
  </code></pre>