fix typo in README.md (#1)

diff --git a/README.md b/README.md
index b8707cc..6daea57 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@
 | 201903@nanjing   | https://yq.aliyun.com/live/908                     |

 | 201901@guangzhou | https://yq.aliyun.com/live/795                     |

 | 201812@hangzhou  | https://yq.aliyun.com/live/652                     |

-| 201809@chendu    | https://yq.aliyun.com/live/500                     |

+| 201809@chengdu    | https://yq.aliyun.com/live/500                     |

 | 201807@shenzhen  | http://www.itdks.com/index.php/Act/apply_upgrade/id/2354/mUid/0.html#dingbu |

 | 201806@Shanghai  | http://www.itdks.com/index.php/Act/apply_upgrade/id/2281/mUid/0.html#dingbu |

 | 201805@Beijing   | http://www.itdks.com/index.php/Act/apply_upgrade/id/2176/mUid/0.html#dingbu |