Merge branch 'libgdx-setup' into 'main'

frontend/core/src/com/game/tankwars/TankWarsGame.java

frontend/desktop/build.gradle

frontend/desktop/src/com/game/tankwars/DesktopLauncher.java

frontend/gradle.properties

frontend/gradle/wrapper/gradle-wrapper.jar

frontend/gradle/wrapper/gradle-wrapper.properties

frontend/gradlew

frontend/gradlew.bat

frontend/html/build.gradle

frontend/html/src/com/game/tankwars/GdxDefinition.gwt.xml

.../html/src/com/game/tankwars/GdxDefinitionSuperdev.gwt.xml

frontend/html/src/com/game/tankwars/client/HtmlLauncher.java

frontend/html/webapp/WEB-INF/web.xml

frontend/html/webapp/index.html

frontend/html/webapp/styles.css

frontend/settings.gradle