function getThemeParameter(name) {
		return new Promise((resolve) => {
			const value = Parameters.get({
				name: name,
				callback: resolve
			});
			if ( value !== undefined ) {
				resolve(value);
			}
		});
	}
Get a theme parameter by its name.

@param {string} name Name of the parameter (without the leading "@" of the less parameter name)
@returns {Promise<string|undefined>} Value of the theme parameter