Hide feedback widget on small screens (#141)

Since the feedback widget is stickied to the bottom of the screen,
on small viewports it can end up taking up a *lot* of real estate.
Enough so that on mobile devices (or when very zoomed), the app
becomes totally unusable.

It's still rough even with the feedback widget hidden, but it's
not nearly as much so.

Author: dlew

client/src/routes/Root.tsx

@@ -107,7 +107,10 @@ export default function Root() {
                     </div>
                   </div>
                 </div>
-                <feedback-widget show-comment-disclaimer="false" skip-email-step="true" />
+                {/* For small screens, the widget blocks too much content, so hide then */}
+                <div className="hidden md:block">
+                  <feedback-widget show-comment-disclaimer="false" skip-email-step="true" />
+                </div>
               </div>
             </PromptGroupsProvider>
           </AgentsMapContext.Provider>