Adding semgrep yaml file

Author: Hrushikesh Deshpande

.github/workflows/semgrep.yml

@@ -0,0 +1,23 @@
+
+on:
+  pull_request: {}
+  workflow_dispatch: {}
+  push: 
+    branches:
+      - main
+      - master
+name: Semgrep config
+jobs:
+  semgrep:
+    name: semgrep/ci
+    runs-on: ubuntu-20.04
+    env:
+      SEMGREP_APP_TOKEN: ${{ secrets.SEMGREP_APP_TOKEN }}
+      SEMGREP_URL: https://cloudflare.semgrep.dev
+      SEMGREP_APP_URL: https://cloudflare.semgrep.dev
+      SEMGREP_VERSION_CHECK_URL: https://cloudflare.semgrep.dev/api/check-version
+    container:
+      image: returntocorp/semgrep
+    steps:
+      - uses: actions/checkout@v3
+      - run: semgrep ci