title: Vertical line in vistime
body: <p>I am having problems getting a vertical line to show in my vistime block of code (to represent the current year, 2021).  Stackoverflow has offered up a plotly (via add_segments) and ggplot (via geom_vline) option to achieve this, but while I dont get an error in the code block, the line doesn't materialize in the plot window. Any advice would be greatly appreciated.  Thankyou.</p>
  <pre><code>library(vistime)
  Wand &lt;- read.csv(text=&quot;event,group,start,end,color,fontcolor
  Mature,Legend,2004-01-01,2009-12-31,#37782C,white
  Seedlings,Legend,2010-01-01,2015-12-31,#9FD983,black
  Absent,Legend,2016-01-01,2021-12-31,#FEFED3,black
  Unknown,Legend,2022-01-01,2027-12-31,#DCDCDC,black
  Burn,Legend,2028-01-01,2033-12-31,#000000,white
  Extirpated :),Legend,2034-01-01,2039-12-31,#024064,white
  ,Caravan Park,2004-01-01,2008-12-31,#37782C,black
  ,Caravan Park,2009-01-01,2010-12-31,#DCDCDC,black
  ,Caravan Park,2011-01-01,2011-12-31,#37782C,black
  ,Caravan Park,2012-01-01,2013-12-31,#DCDCDC,black
  ,Caravan Park,2014-01-01,2014-12-31,#9FD983,black
  ,Caravan Park,2015-01-01,2018-12-31,#DCDCDC,black
  ,Caravan Park,2019-01-01,2020-12-31,#9FD983,black
  Annual Surveillance,Caravan Park,2021-01-01,2026-12-31,#3CB3C0,black
  ,Caravan Park,2027-01-01,2027-12-31,#024064,black
  ,Gravel Pit,2004-01-01,2008-12-31,#37782C,black
  ,Gravel Pit,2009-01-01,2009-12-31,#DCDCDC,black
  ,Gravel Pit,2010-01-01,2010-12-31,#37782C,black
  ,Gravel Pit,2011-01-01,2018-12-31,#DCDCDC,black
  ,Gravel Pit,2019-01-01,2020-12-31,#37782C,black
  Annual Surveillance,Gravel Pit,2021-01-01,2035-12-31,#3CB3C0,black
  ,Gravel Pit,2036-01-01,2036-12-31,#024064,black&quot;)
  gg_vistime(Wand,show_labels = TRUE,background_lines = NULL,optimize_y = TRUE, title = &quot;Town&quot;, linewidth=20)```
  </code></pre>