更新版本预发布例子

README.md

@@ -14,7 +14,8 @@ npm version premajor --no-git-tag-version
 1.0.0 -> 2.0.0-0
 --preid beta | alpha | rc
 npm version prerelease --preid beta --no-git-tag-version
-2.0.0-0 -> 2.0.0-1 -> 2.0.0-2 ..n -> 2.0.0-n
+npm version prerelease
+2.0.0-alpha-0 -> 2.0.0-alpha-1 -> 2.0.0-alpha-2 ..n -> 2.0.0-alpha-n
 npm version patch --no-git-tag-version
 2.0.0-n -> 2.0.0