feat: add blockquote styling

Author: kiaking

src/client/theme-default/styles/layout.css

@@ -184,3 +184,15 @@ td {
   border: 1px solid #dfe2e5;
   padding: 0.6em 1em;
 }
+
+blockquote {
+  margin: 1rem 0;
+  border-left: .2rem solid #dfe2e5;
+  padding: .25rem 0 .25rem 1rem;
+  font-size: 1rem;
+  color: #999;
+}
+
+blockquote > p {
+  margin: 0;
+}