Add MIT License and update README with timer troubleshooting section

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2025 [MiaoMint]
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -11,16 +11,7 @@
 - ✅ **每天重复功能** - 可设置定时器每天自动重复
 - ✅ **单次执行功能** - 执行一次后自动禁用
 - ✅ 定时器状态实时显示
-- ✅ 持### 3. 定时器不工作
-- 确认设备已连接 WiFi（AP 模式下定时器功能受限）
-- 检查系统时间是否已同步（状态页面会显示时间来源）
-- 确认定时器已启用且设置正确
-- 检查引脚连接
-
-### 4. 时间不准确
-- 确认设备已连接到互联网
-- 检查时区设置是否正确
-- 尝试手动触发时间同步（重启设备）配置
+- ✅ 持久化配置储存
 - ✅ **NTP 时间同步** - WiFi 连接时自动同步网络时间
 
 ### 🔌 引脚控制