[dwdunwetter] documentation for binding updated  (#9585)
[dwdunwetter] documentation for binding updated  (#9585)

* Update README.md

examples updated
broken link for CAP DWD Profile fixed
some debugging information added
mapping files renamed to fit naming convention for files containing German language
additional mapping for weather warning added
examples also updated 
mapping files extended with mapping for UNDEF state

MikeJMajor/openhab2-addons-dlinksmarthome,paulianttila/openhab2,paulianttila/openhab2,MikeJMajor/openhab2-addons-dlinksmarthome,paulianttila/openhab2,MikeJMajor/openhab2-addons-dlinksmarthome