style(ui): set line-height to 1.0

src/styles/editor.css

@@ -23,7 +23,7 @@
   outline: none;
   font-family: var(--font-serif);
   font-size: 1.05rem;
-  line-height: 1.7;
+  line-height: 1.0;
   color: var(--color-text);
 }