Prevent zalgo in IRC messages

the overflow: auto; rule is enough to prevent zalgo from drawing over
other IRC messages containing it to a single line.

style.css

@@ -388,6 +388,7 @@ details summary[role="button"] {
 }
 #buffer .logline {
 	white-space: pre-wrap;
+	overflow: auto;
 }
 #buffer .talk, #buffer .motd {
 	color: var(--main-color);