update zh-CN translation of addonsidebarmain (mdn#40742)

Co-authored-by: Dipika Bhattacharya <dipika@foss-community.org>

Author: zhan7236

files/sidebars/addonsidebarmain.yaml

@@ -75,6 +75,7 @@ l10n:
     Forums: 附加组件论坛
     Stack_Overflow: Stack Overflow
     Contact_us: 联系我们
+    "#contact_us": 联系我们
   es:
     Themes: Temas
     Community_and_Support: Comunidad y soporte