Add lal-refactor dependency

Author: joaopsazevedo

README.md

@@ -76,6 +76,7 @@ To build the language server you need:
 * The [gnatdoc](https://github.com/AdaCore/gnatdoc) library
 * The [gpr](https://github.com/AdaCore/gpr) library
 * The process [spawn](https://github.com/AdaCore/spawn) library
+* The [lal-refactor](https://github.com/AdaCore/lal-refactor) library
 
 Project files of the libraries must be available via the `GPR_PROJECT_PATH`
 environment variable.