refactor(img): disable transition effect in popup images

Author: cotes2020

_sass/addon/commons.scss

@@ -703,12 +703,17 @@ i {
 /* --- Overriding --- */
 
 /* magnific-popup */
+
 figure .mfp-title {
   text-align: center;
   padding-right: 0;
   margin-top: 0.5rem;
 }
 
+.mfp-img {
+  transition: none;
+}
+
 /* mermaid */
 .mermaid {
   text-align: center;