Update core-plugins.md

docs/software-developer-documentation/server-side-extensions/core-plugins.md

@@ -289,19 +289,21 @@ following file structure is needed:
 
 **service.properties**
 
-    my-technology
-        1
-          dss
-            drop-boxes
-              my-dropbox
-                lib
-                  my-lib.jar
-                dropbox.py
-                plugin.properties
+```
+my-technology
+    1
+        dss
+        drop-boxes
+            my-dropbox
+            lib
+                my-lib.jar
+            dropbox.py
+            plugin.properties
+```
 
 Having this structure, Java classes from "my-lib.jar" can be imported
 and used in "dropbox.py" script.
 
 NOTICE: Currently this feature is only supported for DSS core
 plugins. Under the hood, a symbolic link to a jar file is created in
-"datastore\_server/lib" folder during DSS startup.
\ No newline at end of file
+"datastore\_server/lib" folder during DSS startup.