[Glitch] Fit the max-width of media in .prose to parent box

Port 0a9def5498 to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/styles/components/privacy_policy.scss

@@ -26,11 +26,13 @@
   img {
     margin-top: 2em;
     margin-bottom: 2em;
+    max-width: 100%;
   }
 
   video {
     margin-top: 2em;
     margin-bottom: 2em;
+    max-width: 100%;
   }
 
   figure {