Add info on tag category colours

docs/UserGuide.md

@@ -225,15 +225,15 @@ Categorizes a tag under a defined category.
 Format: `cattag t/TAG [t/MORE_TAGS]…​ CATEGORY`
 
 * Sets the tag(s) in CampusConnect with the specified name `TAG` to fall under the specified `CATEGORY`.
-* Currently available categories and their respective keywords are:
-
-    Category      | Keyword (case sensitive)
-    --------------|-------------------------
-    **General**   | `general`
-    **Academics** | `acads`
-    **Activities**| `activity`
-    **Networking**| `network`
-    **Mentorship**| `mentor`
+* Currently available categories with their respective keywords and colours are:
+
+    Category      | Keyword (case sensitive) | Colour
+    --------------|--------------------------|-  
+    **General**   | `general`                | <span style="color:DarkGray"> Grey </span>
+    **Academics** | `acads`                  | <span style="color:Gold"> Gold </span>
+    **Activities**| `activity`               | <span style="color:DodgerBlue"> Blue </span>
+    **Networking**| `network`                | <span style="color:LimeGreen"> Green </span>          
+    **Mentorship**| `mentor`                 | <span style="color:HotPink"> Pink </span>
 * Multiple tags can be categorized to the same category at a time.
 * All tags specified must be valid existing tags.
 * Attempts to set a tag to its current category will cause the whole command to be rejected.