Update Dockerfile to the multi-module project structure

Author: fwcd

Dockerfile

@@ -1,12 +1,13 @@
 # Running this container will start a language server that listens for TCP connections on port 2088
 # Every connection will be run in a forked child process
 
-# Please note that before building the image, you have to build the language server with `./gradlew build`
+# Please note that before building the image, you have to build the language server with `./gradlew :server:installDist`
 
 FROM openjdk:10
 
-COPY ./build/install ./
+WORKDIR /
+COPY server/build/install/server .
 
 EXPOSE 2088
 
-CMD ["./kotlin-language-server/bin/kotlin-language-server", "--tcp-server=0:2088"]
+CMD ["/server/bin/kotlin-language-server", "--tcpPort=2088"]