Add channel redirect

src/invidious/views/channel.ecr

@@ -41,6 +41,9 @@
 <div class="pure-g h-box">
     <div class="pure-u-1-3">
         <a href="https://www.youtube.com/channel/<%= channel.ucid %>"><%= translate(locale, "View channel on YouTube") %></a>
+        <div class="pure-u-1 pure-md-1-3">
+            <a href="/redirect?referer=<%= env.get?("current_page") %>"><%= translate(locale, "Switch Invidious Instance") %></a>
+        </div>
         <% if !channel.auto_generated %>
             <div class="pure-u-1 pure-md-1-3">
                 <b><%= translate(locale, "Videos") %></b>