titlebar: Create a title bar
In rstudio/shinygadgets: UI Toolkit for Shiny

Creates a title bar for a Shiny Gadget. Intended to be used with gadgetPage. Title bars contain a title, and optionally, a titlebarButton on the left and/or right sides.

titlebar(title, left = NULL, right = titlebarButton("done", "Done", primary
  = TRUE))

titlebarButton(inputId, label, primary = FALSE)

`title`	The title of the gadget. If this needs to be dynamic, pass `textOutput` with `inline = TRUE`.
`left`	The `titlebarButton` to put on the left, or `NULL` for none.
`right`	The `titlebarButton` to put on the right, or `NULL` for none. Defaults to a primary "Done" button that can be handled using `observeEvent(input$done, {...})`.
`inputId`	The `input` slot that will be used to access the button.
`label`	The text label to display on the button.
`primary`	If `TRUE`, render the button in a bold color to indicate that it is the primary action of the gadget.