Add discouragement reason to SVG 1.1

Author: ddbeck

features/svg-discouraged.yml

@@ -4,6 +4,7 @@ spec: https://www.w3.org/TR/SVG11/
 discouraged:
   according_to:
     - https://svgwg.org/svg2-draft/changes.html#substantial
+  reason: SVG 2 omittted some parts of SVG 1.1 to "improv[e] the usability and precision of the language."
   alternatives:
     - svg
     - font-face