Install psalm as dev, sync scripts updates

vendor/felixfbecker/language-server-protocol/src/ResourceOperationKind.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace LanguageServerProtocol;
+
+/**
+ * Defines how the host (editor) should sync document changes to the language server.
+ */
+abstract class ResourceOperationKind
+{
+    /**
+     * Supports creating new files and folders.
+     */
+    const CREATE = 'create';
+
+    /**
+     * Supports renaming existing files and folders.
+     */
+    const RENAME = 'rename';
+
+    /**
+     * Supports deleting existing files and folders.
+     */
+    const DELETE  = 'delete';
+}