chore(nx): add whole .nx directory to gitignore

According to nrwl/nx#26519 `.nx/workspace-data` should be also ignored.
NX suggests now to ignore whole `.nx` directory.

Author: wszydlak

.gitignore

@@ -39,7 +39,7 @@ testem.log
 Thumbs.db
 
 # Nx
-.nx/cache
+.nx
 migrations.json
 
 # Angular