Update footer.rst

Removes redundant reference to Discord asset.

docs/footer.rst

@@ -124,16 +124,6 @@
    </script>
 
 
-.. note - this ensures that the Sphinx build system will pull in the image (as it is referenced in an RST file) to _images,
-   we don't want to display it via rst markup due to limitations (hence width:0), however we do want it available for our raw HTML
-   which we use in header.rst.
-
-.. image:: images/discord-mark-blue.svg
-          :alt:
-          :width: 0
-          :height: 0
-          :target: https://discord.gg/zpyAHM7XtF
-
 
 .. external links