Adapt readme, remove gradle references

RISDEV-0000

.github/dependabot.yml

@@ -2,10 +2,6 @@
 # https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
 version: 2
 updates:
-  - package-ecosystem: "gradle"
-    directory: "/"
-    schedule:
-      interval: "daily"
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:

.github/workflows/pipeline.yml

@@ -1,6 +1,3 @@
-# This workflow will build a Java project with Gradle and cache/restore any dependencies to improve the workflow execution time
-# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-gradle
-
 name: Pipeline
 
 on:

README.md

@@ -61,10 +61,10 @@ If you need to push a new container image to the registry manually there are two
 **Via built-in Gradle task:**
 
 ```bash
-export CONTAINER_REGISTRY=ghcr.io
-export CONTAINER_IMAGE_NAME=digitalservicebund/ris-norms-migration-import
-export CONTAINER_IMAGE_VERSION="$(git log -1 --format='%H')"
-CONTAINER_REGISTRY_USER=[github-user] CONTAINER_REGISTRY_PASSWORD=[github-token] ./gradlew bootBuildImage --publishImage
+IMAGE_VERSION="$(git log -1 --format='%H')"
+docker build -t ghcr.io/digitalservicebund/ris-norms-migration-import:$IMAGE_VERSION .
+echo [github-token] | docker login ghcr.io -u [github-user] --password-stdin
+docker push ghcr.io/digitalservicebund/ris-norms-migration-import:$IMAGE_VERSION
 ```
 
 **Note:** Make sure you're using a GitHub token with the necessary `write:packages` scope for this to work.
@@ -93,7 +93,7 @@ brew install aquasecurity/trivy/trivy
 ```
 
 ```bash
-./gradlew bootBuildImage
+docker build -t ghcr.io/digitalservicebund/ris-norms-migration-import:latest .
 trivy image --severity HIGH,CRITICAL ghcr.io/digitalservicebund/ris-norms-migration-import:latest
 ```