feat: message format, pretty markdown

frontend/src/assets/main.css

@@ -94,4 +94,14 @@ input:disabled, textarea:disabled, select:disabled {
 
 .with-sidebar-expanded .when-sidebar-collapsed {
   display: none;
+}
+
+/* Content */
+h1, h2, h3, h4, h5, h6 {
+  margin: 1em 0 0.5em;
+  font-weight: bold;
+}
+
+p, ul, il {
+  margin: 0.5em 0;
 }