Added SEF to the hacktoberlist

docs/list.md

@@ -362,6 +362,18 @@ Appwrite is a self-hosted backend-as-a-service platform that provides developers
 
 ### S
 
+#### **SEF**
+
+- **Swag**: T-shirt, stickers, and coupons.
+- **Requirements**: Make 4 valid PRs against open issues.
+- **How to sign up**: No Special sign up known.
+- **Issues** : 
+    - [SEF ScholarX Frontend](https://github.com/sef-global/scholarx-frontend/issues) 
+    - [SEF ScholarX Backend](https://github.com/sef-global/scholarx-backend/issues?q=is%3Aopen+is%3Aissue+label%3Ahacktoberfest)
+    - [SEF Site](https://github.com/sef-global/sef-site)
+    - [SEF Handbook](https://github.com/sef-global/sef-handbook)
+- **Notes**: Visit [SEF - Sustainable Education Foundation](https://sef.discourse.group/t/it-s-hacktoberfest-month/543) to know more about it.
+
 #### **ServiceNow**
 
 - **Swag**: CreatorCon T-shirt, ServiceNow Merchandise