update .gitignore, modify Docker Hub credentials in workflow, and add usage instructions to README

.gitea/workflows/build.yml

@@ -25,8 +25,8 @@ jobs:
       - name: 🔑 🔐 Login to Docker Hub
         uses: docker/login-action@v3
         with:
-          username: ${{ secrets.DOCKER_USERNAME }}
-          password: ${{ secrets.DOCKER_PASSWORD }}
+          username: ${{ secrets.SITEWORX_USERNAME }}
+          password: ${{ secrets.SITEWORX_PASSWORD }}
 
       - name: 🏗️ 🔧 Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
@@ -39,4 +39,4 @@ jobs:
           platforms: linux/arm64,linux/amd64
           context: .
           dockerfile: Dockerfile
-          tags: siteworxpro/gun-manager:${{ gitea.ref_name }}
+          tags: scr.siteworxpro.com/gun-manager:${{ gitea.ref_name }}