Docs update for minimizing SVG illustrations

doc/development/fe_guide/icons.md

@@ -198,3 +198,10 @@ export default {
   <img :src="svgIllustrationPath" />
 </template>
 ```
+
+### Minimize SVGs
+
+When you develop or export a new SVG illustration, minimize it with an [SVGO](https://github.com/svg/svgo) powered tool, like
+[SVGOMG](https://jakearchibald.github.io/svgomg/), to save space. Illustrations
+added to [GitLab SVG](https://gitlab.com/gitlab-org/gitlab-svgs) are automatically
+minimized, so no manual action is needed.