doc: Add comment

Author: CGNonofr

scripts/install-extensions

@@ -1,6 +1,9 @@
 #!/bin/bash
 set -e
 
+# In java, the vscode extension contains a lot of code to implements advanced features (jdt files provider, inlay hints, source action commands...)
+# Instead of copy-pasting this code, let's download it, build it and import it from our code
+
 mkdir -p "`pwd`/extensions"
 output_directory="`pwd`/extensions/java"
 rm -rf $output_directory