minor fix in GraalPyResources javadoc

Author: tomasstupka

docs/user/Troubleshooting.md

@@ -89,6 +89,14 @@ For more details about GraalPy context and Virtual FileSystem configuration plea
 
 ### Maven and Gradle applications
 
+####  ImportError reports "unknown location"
+A possible cause of an `ImportError` ending with `(unknown location)` when running a GraalPy Java Embedding project might be 
+that an embedded Python package was built for a different operating system. If you see an error like the following:
+```
+ImportError: cannot import name 'exceptions' from 'cryptography.hazmat.bindings._rust' (unknown location)
+``` 
+You probably need to rebuild your project on the correct operating system before running it.
+
 #### GraalVM JDK Compatibility
 To enable runtime compilation when running GraalPy from a Maven or Gradle application, 
 you must use versions of GraalPy and the Polyglot API dependencies that are compatible 

graalpython/org.graalvm.python.embedding/src/org/graalvm/python/embedding/GraalPyResources.java

@@ -76,10 +76,12 @@
  * </p>
  *
  * <p>
- * In order to make this work, it is necessary for those embedded resources to have their <b>root
- * directory</b> set to <code>/org.graalvm.python.vfs</code> which in python code will be mapped to
- * the virtual filesystem <b>mount point</b>, by default <code>/graalpy_vfs</code>. Refer to
- * {@link VirtualFileSystem.Builder} documentation for more details.
+ * In order to make this work, it is necessary for those embedded resources to have a common
+ * <b>resource root directory</b>. The default value is <code>/org.graalvm.python.vfs</code>,
+ * however the recommended convention is to use {@code GRAALPY-VFS/{groupId}/{artifactId}}. This
+ * root directory will then be in python code mapped to the virtual filesystem <b>mount point</b>,
+ * by default <code>/graalpy_vfs</code>. Refer to
+ * {@link VirtualFileSystem.Builder#resourceDirectory(String)} documentation for more details.
  * </p>
  *
  * <h3>External Directory</h3>