[Documentation:InstructorUI] fix drop lowest description (#564)

![Screen Shot 2023-11-11 at 11 34 43
PM](https://github.com/Submitty/submitty.github.io/assets/123261952/788a8d0f-b7ec-492a-9957-00af57c4a113)


It was missing a delimiter, now it does

_docs/instructor/course_settings/rainbow_grades/manual_setup.md

@@ -184,19 +184,22 @@ redirect_from:
 Although it is not yet implemented in web-GUI, RainbowGrades support drop lowest grade.
 Directly edit the customization.json file
 Here is a example usage, removing one lowest gradeable from given type
-``` 
+
+  ```json
 {
-   “count”: 8,
-   “percent”: 0.12,
-   “type”: “quiz”,
-   “remove_lowest”: 1,
-   “ids”: [
-      {
-      “max”: 10.0,
-      “id”: “quiz01",
-      “percent”: 0.125,
-      “released”: true
-      },
-...
+  "count": 8,
+  "percent": 0.12,
+  "type": "quiz",
+  "remove_lowest": 1,
+  "ids": [
+    {
+      "max": 10.0,
+      "id": "quiz01",
+      "percent": 0.125,
+      "released": true
+    }
+     ]
+}
+  ```