Use JDK 11 instead of JDK 8, but only for Docker container to allow usage of skeleton project in the same pipeline

Updated main description in README.md, updated answer to a question, use static variable for sleeping

Refactored TinybUtil to FindDevicesManager, ensure that we search long enough until a device can be found, extended tests

Added intention of this project to README.md and use xml markdown instead of shell for bluetooth policy