chore: update coverage badge in README and add GitHub Actions workflow for badge generation

Author: Mathious6

.github/workflows/coverage-badge.yml

@@ -0,0 +1,44 @@
+name: Generate code coverage badge
+on:
+  push:
+    branches:
+      - M6/feat/v1
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    name: Update coverage badge
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+          fetch-depth: 0
+      - name: Setup go
+        uses: actions/setup-go@v4
+        with:
+          go-version: '1.24'
+      - name: Test
+        run: |
+          go test -v ./... -covermode=count -coverprofile=coverage.out
+          go tool cover -func=coverage.out -o=coverage.out
+      - name: Go Coverage Badge
+        uses: tj-actions/coverage-badge-go@v3
+        with:
+          filename: coverage.out
+      - name: Verify Changed files
+        uses: tj-actions/verify-changed-files@v20
+        id: verify-changed-files
+        with:
+          files: README.md
+      - name: Commit changes
+        if: steps.verify-changed-files.outputs.files_changed == 'true'
+        run: |
+          git config --local user.email "action@github.com"
+          git config --local user.name "GitHub Action"
+          git add README.md
+          git commit -m "chore: Updated coverage badge."
+      - name: Push changes
+        if: steps.verify-changed-files.outputs.files_changed == 'true'
+        uses: ad-m/github-push-action@master
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          branch: ${{ github.ref_name }} 

README.md

@@ -2,7 +2,7 @@
 
 [![CI](https://github.com/Mathious6/platekit/actions/workflows/ci.yml/badge.svg)](https://github.com/Mathious6/platekit/actions)
 [![Go Reference](https://pkg.go.dev/badge/github.com/Mathious6/platekit.svg)](https://pkg.go.dev/github.com/Mathious6/platekit)
-[![Coverage Status](https://coveralls.io/repos/github/Mathious6/platekit/badge.svg?branch=main)](https://coveralls.io/github/Mathious6/platekit?branch=main)
+[![Coverage Status](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/Mathious6/PLATEKIT_COVERAGE_GIST/raw/coverage-badge.json)](https://github.com/Mathious6/platekit/actions/workflows/coverage-badge.yml)
 
 Go library to generate deterministic random license‑plate strings (format `XX-000-000-XX`) from seeds or input strings.