title: How to scroll up in Vim buffer with R (using Nvim-R)
body: <p>I'm a happy user of the <a href="https://github.com/jalvesaq/Nvim-R" rel="noreferrer">Nvim-R</a> plugin, but I cannot find out how to scroll up in the buffer window that the plugin opens with R. Say for instance that I have a large output in console, but I cannot see the top of it - how do I scroll up to see this? In tmux for instance there's a copy mode that quite handily lets you do this, but how is this done in the R buffer?</p>
  
  <p>An example below where I'm very curious to see what's on the line above the one begining with "is.na(a)...". How can this be achieved?</p>
  
  <p>I have scoured the documentation found <a href="https://raw.githubusercontent.com/jalvesaq/Nvim-R/master/doc/Nvim-R.txt" rel="noreferrer">here</a>, but without luck.</p>
  
  <p><a href="https://i.stack.imgur.com/UHVX2.png" rel="noreferrer"><img src="https://i.stack.imgur.com/UHVX2.png" alt="enter image description here"></a></p>