Convert build.gradle to build.gradle.kts again

[Quillraven]

For whatever reason there was an issue that the DesktopLauncherKt main class could not be found when running the DesktopLauncher from Intellij.

I reverted the build.gradle.kts files now to groovy build.gradle files, deleted the .idea/.gradle folder, cleaned the project, deleted the .iml project file and reimported the project with the build.gradle file.

Now I have three modules - desktop, core, android - all on the same level and I am able to run the DesktopLauncher again from Intellij and also I can run android.

Will try to convert to build.gradle.kts again once I finished some other stuff for the project.

related PR: #9

[Quillraven]

@DRSchlaubi
I have updated the master branch with most of the things we did yesterday:

• Java version is now 8
• jvm target for kotlin is 1.8
• android res and manifest file moved
• asset folder moved to root
• Dependencies.kt moved ot kotlin source folder instead of java

buildscript is still in the rootproject as we were not able to get rid off it by still using the buildSrc.

This is nothing super urgent since the project is building and deploying successfully. Once we find a solution for the android buildSrc problem we can of course still apply it.

Thanks again for your time yesterday and for working so late ;)