title: add popovers to shiny app?
body: <p>I would like to add a (?) next to the title of a widget so that the user can hover or click it and get extra information and a link they can click.</p>
  
  <p>This is what I have right now:</p>
  
  <pre><code>## app.R ##
  library(shiny)
  library(shinydashboard)
  library(shinyBS)
  # Header
  header &lt;- dashboardHeader()
  # Sidebar
  sidebar &lt;- dashboardSidebar(fileInput("chosenfile", label = h4("File input"), 
                                        accept = ".csv"),
                              bsButton("q1", label = "", icon = icon("question"),
                                       style = "info", size = "extra-small"),
                              bsPopover(id = "q1", title = "Tidy data",
                                        content = paste0("You should read the ", 
                                                         a("tidy data paper", 
                                                           href = "http://vita.had.co.nz/papers/tidy-data.pdf",
                                                           target="_blank")),
                                        placement = "right", 
                                        trigger = "click", 
                                        options = list(container = "body")
                                        )
                              )
  # Body
  body &lt;- dashboardBody()
  # ui
  ui &lt;- dashboardPage(header, sidebar, body)
  # server
  server &lt;- function(input, output) {
  
  }
  # run
  shinyApp(ui, server)
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/Hj8Pp.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Hj8Pp.png" alt="popover"></a></p>
  
  <p>But it is far from perfect. For example the placement of the (?) is not next to "File input" and to close the popover you have to click the question mark again instead of having an (x) in the popover. </p>