Navbar hides initial content when jumping to in-page anchor

See twbs/bootstrap#1768 for details.

src/sphinxjp/themes/basicstrap/templates/basicstrap/layout.html

@@ -124,6 +124,24 @@
        }
     });
   });
+  $(window).load(function () {
+    /*
+
+     * Scroll the window to avoid the topnav bar
+     * https://github.com/twitter/bootstrap/issues/1768
+     */
+    if ($(".navbar.navbar-fixed-top").length > 0) {
+      // var navHeight = $(".navbar").height(),
+      var navHeight = 40,
+        shiftWindow = function() { scrollBy(0, -navHeight - 10); };
+
+      if (location.hash) {
+        setTimeout(shiftWindow, 1);
+      }
+
+      window.addEventListener("hashchange", shiftWindow);
+    }
+  });
 </script>
 {%- endmacro %}