add Code Scanning badge

Author: szdytom

.github/workflows/codeql-analysis.yml

@@ -1,4 +1,4 @@
-name: "CodeQL"
+name: "CodeQL Analyze"
 
 on:
   push:

README.md

@@ -8,7 +8,7 @@ A OnlineJudge using Django and Docker.
 [![Repo Size](https://img.shields.io/github/repo-size/szdytom/segmentoj)](https://github.com/szdytom/segmentoj/)
 [![Python 3](https://pyup.io/repos/github/segment-oj/segmentoj/python-3-shield.svg)](https://pyup.io/repos/github/segment-oj/segmentoj/)
 [![Updates](https://pyup.io/repos/github/segment-oj/segmentoj/shield.svg)](https://pyup.io/repos/github/segment-oj/segmentoj/)
-![visitors](https://visitor-badge.laobi.icu/badge?page_id=segmentoj)
+![CodeQL](https://github.com/segment-oj/segmentoj/workflows/CodeQL%20Analyze/badge.svg)
 
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