Shortcut to copy URL of original page (alt + C)

Fixes #1199.

assets/javascripts/app/shortcuts.coffee

@@ -149,6 +149,9 @@ class app.Shortcuts
       when 40
         @trigger 'altDown'
         false
+      when 67
+        @trigger 'altC'
+        false
       when 68
         @trigger 'altD'
         false

assets/javascripts/news.json

@@ -1,4 +1,8 @@
 [
+  [
+    "2021-04-29",
+    "Added <code class=\"_label\">alt + c</code> shortcut to copy URL of original page."
+  ],
   [
     "2021-02-26",
     "New documentation: <a href=\"/react_bootstrap/\">React Bootstrap</a>"

assets/javascripts/templates/pages/help_tmpl.coffee

@@ -130,6 +130,9 @@ app.templates.helpPage = ->
   </dl>
   <h3 class="_shortcuts-title">Miscellaneous</h3>
   <dl class="_shortcuts-dl">
+    <dt class="_shortcuts-dt">
+      <code class="_shortcut-code">alt + c</code>
+    <dd class="_shortcuts-dd">Copy URL of original page
     <dt class="_shortcuts-dt">
       <code class="_shortcut-code">alt + o</code>
     <dd class="_shortcuts-dd">Open original page

assets/javascripts/views/content/entry_page.coffee

@@ -6,6 +6,7 @@ class app.views.EntryPage extends app.View
     click: 'onClick'
 
   @shortcuts:
+    altC: 'onAltC'
     altO: 'onAltO'
 
   @routes:
@@ -153,6 +154,12 @@ class app.views.EntryPage extends app.View
       setTimeout (-> target.className = '_pre-clip'), 2000
     return
 
+  onAltC: =>
+    return unless link = @find('._attribution:last-child ._attribution-link')
+    console.log(link.href + location.hash)
+    navigator.clipboard.writeText(link.href + location.hash)
+    return
+
   onAltO: =>
     return unless link = @find('._attribution:last-child ._attribution-link')
     @delay -> $.popup(link.href + location.hash)