Replace symlink with copy

GitHub Actions Marketplace does not seem to support symlinks yet

Author: jonico

Dockerfile

@@ -0,0 +1,15 @@
+FROM jonico/jenkinsfile-runner-github-action
+
+LABEL "com.github.actions.name"="Jenkinsfile Runner Prepackaged"
+LABEL "com.github.actions.description"="Runs Jenkinsfile in a pre-packaged single-shot master"
+LABEL "com.github.actions.icon"="battery"
+LABEL "com.github.actions.color"="blue"
+
+LABEL "repository"="http://github.com/jonico/jenkinsfilerunner-github-actions"
+LABEL "homepage"="http://github.com/actions"
+LABEL "maintainer"="Johannes Nicolai <jonico@github.com>"
+
+ENTRYPOINT ["/app/bin/jenkinsfile-runner", \
+            "-w", "/app/jenkins",\
+            "-p", "/usr/share/jenkins/ref/plugins",\
+            "-f", "/github/workspace"]