Decrease the default idle parse delay in the script editor

This makes errors reported 0.5 seconds faster compared to the previous
default value, and is closer to other code editors' behavior such as
VS Code.

editor/editor_settings.cpp

@@ -662,7 +662,7 @@ void EditorSettings::_load_defaults(Ref<ConfigFile> p_extra_config) {
 	_initial_set("text_editor/script_list/sort_members_outline_alphabetically", false);
 
 	// Completion
-	EDITOR_SETTING(Variant::FLOAT, PROPERTY_HINT_RANGE, "text_editor/completion/idle_parse_delay", 2.0, "0.1,10,0.01")
+	EDITOR_SETTING(Variant::FLOAT, PROPERTY_HINT_RANGE, "text_editor/completion/idle_parse_delay", 1.5, "0.1,10,0.01")
 	_initial_set("text_editor/completion/auto_brace_complete", true);
 	_initial_set("text_editor/completion/code_complete_enabled", true);
 	EDITOR_SETTING(Variant::FLOAT, PROPERTY_HINT_RANGE, "text_editor/completion/code_complete_delay", 0.3, "0.01,5,0.01,or_greater")