This function returns a set of web dependencies necessary for using Bootstrap components in a web page.
bootstrapLib(theme = NULL)Alternative Bootstrap stylesheet (normally a css file within the
www directory, e.g. www/bootstrap.css)
It isn't necessary to call this function if you use
bootstrapPage or others which use bootstrapPage, such
basicPage, fluidPage, fillPage,
pageWithSidebar, and navbarPage, because they
already include the Bootstrap web dependencies.