title: Cannot see Python function documentation in R with reticulate
body: <p>I'm running into an issue on RStudio (1.4) where I cannot see Python documentation in the Help Panel. I'm using <code>reticulate</code> v. 1.20 and my Python interpreter is working fine. But if I use the F1 keyboard shortcut or run e.g., <code>?np.random.rand</code> I get the following error:</p>
  <pre><code>&gt;&gt;&gt; ?np.random.rand
  Error in html$page(pydoc$describe(resolved), html$document(resolved, name)) : 
    attempt to apply non-function
  Error in html$page(pydoc$describe(resolved), html$document(resolved, name)) : 
    attempt to apply non-function
  Error in html$page(pydoc$describe(resolved), html$document(resolved, name)) : 
    attempt to apply non-function
  </code></pre>
  <p>The Help panel reads: /python/np.random.rand.html not found</p>
  <p>Haven't seen this issue anywhere else.</p>