[skip-ci] increase debug logging documentation

Author: ddsharpe

imagetool/src/main/bin/logging.properties

@@ -16,6 +16,7 @@ handlers=java.util.logging.ConsoleHandler
 #
 
 com.oracle.weblogic.imagetool.level=INFO
+#com.oracle.weblogic.imagetool.level=FINER
 
 #
 # Change log file location and handlers logging level as needed. Note the default level for FileHandler is OFF

site/logging.md

@@ -1,8 +1,31 @@
 # Logging
 
-In some circumstances, it may be helpful to turn on debugging to reveal more information.  
+The Image Tool uses standard Java logging. To alter the default logging settings, you can modify the `logging.properties` 
+file under the ```bin``` directory where you installed the Image Tool.
 
-The Image Tool uses the standard `logging.properties` file under the tool's ```bin``` directory.
+### To enable debug logging
+In `logging.properties`, comment the existing `handlers` property and uncomment the `handlers` line below the first that 
+contains the FileHandler.
+```properties
+#handlers=java.util.logging.ConsoleHandler
+handlers=java.util.logging.FileHandler, java.util.logging.ConsoleHandler
+```
+Then, change the Level to `FINE` or `FINER`.
+```properties
+#com.oracle.weblogic.imagetool.level=INFO
+com.oracle.weblogic.imagetool.level=FINER
+```
+
+Logging levels from highest to lowest:
+
+| Level | Description |
+| --- | --- |
+| `SEVERE` | Only error messages will be written to the log file. |
+| `WARNING` | Warning messages and above will be written to the log file. |
+| `INFO` | (Default) Informational messages and above will be written to the log file. |
+| `FINE` | First level of debug messages and above are written to the log file. |
+| `FINER` | Detailed debug messages and above are written to the log file. |
+| `FINEST` | All HTTP responses in addition to `FINER` level debug messages are written to the log file. |
 
 ### Copyright
 Copyright (c) 2019, 2020, Oracle and/or its affiliates.