added Dockerfile, preparing for distribution

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

de.srsoftware.cal.app/build.gradle.kts

@@ -1,5 +1,9 @@
 description = "OpenCloudCal : Application"
 
+plugins {
+    application
+}
+
 dependencies {
     implementation(project(":de.srsoftware.cal.api"))
     implementation(project(":de.srsoftware.cal.base"))
@@ -11,10 +15,14 @@ dependencies {
     implementation("de.srsoftware:configuration.json:1.0.0")
 
     implementation("de.srsoftware:tools.http:1.2.2")
-    implementation("de.srsoftware:tools.logging:1.0.5")
+    implementation("de.srsoftware:tools.logging:1.2.0")
     implementation("de.srsoftware:tools.plugin:1.0.1")
     implementation("de.srsoftware:tools.util:1.3.0")
     implementation("de.srsoftware:tools.web:1.3.14")
     implementation("com.mysql:mysql-connector-j:9.1.0")
     implementation("org.json:json:20240303")
 }
+
+application{
+    mainClass = "de.srsoftware.cal.app.Application"
+}