some chat component visual improvements

src-ui/src/app/components/chat/chat/chat.component.scss

@@ -36,3 +36,19 @@
     opacity: 1;
   }
 }
+
+.chat-markdown ::ng-deep {
+  h1, h2, h3, h4, h5, h6 {
+    font-size: 1em;
+    font-weight: bold;
+  }
+
+  th, td {
+    padding: 0.15rem 0.4rem;
+    border: 1px solid var(--bs-border-color);
+  }
+
+  > :last-child {
+    margin-bottom: 0;
+  }
+}