style: format less, add annotation

Author: qingmo.xwj

__tests__/variable.less

@@ -1,2 +1,2 @@
-@blue:blue;
-@size:10px;
+@blue: blue;
+@size: 10px;

src/index.ts

@@ -11,6 +11,7 @@ interface Transformer {
 /**
  * transform less sync
  * @param fileContent
+ * @param filePath
  */
 function transformLess(fileContent: string, filePath: string): string {
   const data = fileContent.replace(/^\uFEFF/, '');