Mod Config: Add API method to store a config value

[KANAjetzt]

Currently, the only way to update the config file is via ModLoaderConfig.update_config(). Adding a method to update a specific value within the config would be a nice quality-of-life improvement.

godot-mod-loader/addons/mod_loader/api/config.gd

Lines 72 to 101 in aab3aaa

	## Updates an existing [ModConfig] object with new data and saves the config file.[br]
	## [br]
	## [b]Parameters:[/b][br]
	## - [code]config[/code] ([ModConfig]): The [ModConfig] object to be updated.[br]
	## [br]
	## [b]Returns:[/b][br]
	## - [ModConfig]: The updated [ModConfig] object if successful, or null otherwise.
	static func update_config(config: ModConfig) -> ModConfig:
	# Validate the config and check for any validation errors
	var error_message := config.validate()
	# Check if the config is the "default" config, which cannot be modified
	if config.name == DEFAULT_CONFIG_NAME:
	ModLoaderLog.error("The \"default\" config cannot be modified. Please create a new config instead.", LOG_NAME)
	return null
	# Check if the config passed validation
	if not config.is_valid:
	ModLoaderLog.error("Update for config \"%s\" failed validation with error message \"%s\"" % [config.name, error_message], LOG_NAME)
	return null
	# Save the updated config to the config file
	var is_save_success := config.save_to_file()
	if not is_save_success:
	ModLoaderLog.error("Failed to save config \"%s\" to \"%s\"." % [config.name, config.save_path], LOG_NAME)
	return null
	# Return the updated config
	return config