Updated Directory Tree (markdown)

Directory-Tree.md

@@ -2,6 +2,9 @@ By default, exporting results in a directory tree compatible with the [3dcam eng
 
 This can be overridden at export time with the ['Use Blender filename' option](https://github.com/ABelliqueux/blender_io_export_psx_mesh/wiki/Export-Options).
 
+**For now the exported files names will always follow this pattern. The filename in Blender's export dialog is not used.  
+You'll have to manually rename the files in `levels` and in the engine's sources if you insist on using another name.**
+
 # Default tree
 ```
 .
@@ -13,6 +16,16 @@ This can be overridden at export time with the ['Use Blender filename' option](h
 
 2 directories, 3 files
 ```
+# Incrementing the filename
+
+Use 'Level Number' to increment your levels ; i.e : Setting level number to 1 will result in 
+```
+├── levels
+│   ├── level1.c
+│   └── level1.h
+```
+and all the C symbols in the generated files will use this prefix as well.
+
 
 # Case of unsaved file