Update README.md

Author: Mercurio

README.md

@@ -4,6 +4,14 @@
 
 A [Flarum](http://flarum.org) extension. Make the sidenav section sticky and scrollable. Also support hot-discussions widget.
 
+## Scrollbar
+
+Usually when we make the sidenav section sticky, we have to scroll to the bottom of the page to view the tags that are not shown in the first place. This extension resolves the problem by making the sidenav scrollable.
+
+The scrollbar will appear only if there are too many tags AND the mouse is hovering above the sidenav. Example screenshot:
+
+![image](https://user-images.githubusercontent.com/32540679/162741325-5e3bdc75-424e-49ff-ae8f-8756a2d15a39.png)
+
 ## Installation
 
 Install with composer:

composer.json

@@ -2,7 +2,9 @@
     "name": "ecnu-im/sticky-sidenav",
     "description": "Make the sidenav section sticky and scrollable. Also support hot-discussions widget.",
     "keywords": [
-        "flarum"
+        "flarum",
+        "sticky",
+        "sidenav"
     ],
     "type": "flarum-extension",
     "license": "MIT",
@@ -19,11 +21,11 @@
     "extra": {
         "flarum-extension": {
             "title": "Sticky Sidenav",
-            "category": "",
+            "category": "theme",
             "icon": {
-                "name": "",
-                "color": "",
-                "backgroundColor": ""
+                "name": "fas fa-map-pin",
+                "color": "#fff",
+                "backgroundColor": "#f28326"
             }
         },
         "flarum-cli": {