padOsd: Work around xgettext confusion

Similar to the previous work-around, xgettext gets thrown off by
embedded quotes in template strings, in particular where a template
"breaks up" a pair of quotes.

Throw in some more comments to make xgettext happy, but whoever makes
the gettext toolchain not depend on fragile regular expressions will
be drowned in beverages of their choice ...

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/792

js/ui/padOsd.js

@@ -350,7 +350,9 @@ var PadDiagram = GObject.registerClass({
         return ('<?xml version="1.0" encoding="UTF-8" standalone="no"?>' +
                 '<svg version="1.1" xmlns="http://www.w3.org/2000/svg" ' +
                 'xmlns:xi="http://www.w3.org/2001/XInclude" ' +
-                `width="${this._imageWidth}" height="${this._imageHeight}"> ` +
+                `width="${ // " (give xgettext the paired quotes it expects)
+                    this._imageWidth
+                }" height="${this._imageHeight}"> ` + // "
                 '<style type="text/css">');
     }