#27 document appender with type "rollingfile"

[Kalle Richter]

It is unclear who's responsible for creating files and directories referenced in the log4crc configuration file. In the 1.2.4 tarball running the example project with the appender myrollingfileappender doesn't produce any log files in the examples directory. Is that intended or a bug? Please clarify (not necessarily here, but in the docs).