Move terminal CSS into LESS file

IPython/html/static/notebook/less/terminal.less

@@ -11,3 +11,7 @@
   color: black;
   background: white;
 }
+
+#terminado-container {
+    margin: 8px;
+}

IPython/html/static/style/style.min.css

@@ -10495,4 +10495,7 @@ span#autosave_status {
   color: black;
   background: white;
 }
+#terminado-container {
+  margin: 8px;
+}
 /*# sourceMappingURL=../style/style.min.css.map */

IPython/html/static/terminal/css/override.css

@@ -1,7 +0,0 @@
-/*This file contains any manual css for this page that needs to override the global styles.
-This is only required when different pages style the same element differently. This is just
-a hack to deal with our current css styles and no new styling should be added in this file.*/
-
-#terminado-container {
-    margin: 8px;
-}