feat(school_stm32): 添加基础的 STM32F103RCT6 项目结构

- 创建了项目的基本目录结构和文件
- 添加了 CMakeLists.txt 和 Makefile 构建配置
- 创建了 main.c 文件，实现了简单的 LED 闪烁和按键检测功能
- 集成了 SEGGER RTT 库
- 添加了 .gitignore 文件，排除了不必要的生成文件

libs/SEGGER_RTT/Examples/Main_RTT_InputEchoApp.c

@@ -0,0 +1,80 @@
+/*********************************************************************
+*                    SEGGER Microcontroller GmbH                     *
+*                        The Embedded Experts                        *
+**********************************************************************
+*                                                                    *
+*            (c) 1995 - 2021 SEGGER Microcontroller GmbH             *
+*                                                                    *
+*       www.segger.com     Support: support@segger.com               *
+*                                                                    *
+**********************************************************************
+*                                                                    *
+*       SEGGER RTT * Real Time Transfer for embedded targets         *
+*                                                                    *
+**********************************************************************
+*                                                                    *
+* All rights reserved.                                               *
+*                                                                    *
+* SEGGER strongly recommends to not make any changes                 *
+* to or modify the source code of this software in order to stay     *
+* compatible with the RTT protocol and J-Link.                       *
+*                                                                    *
+* Redistribution and use in source and binary forms, with or         *
+* without modification, are permitted provided that the following    *
+* condition is met:                                                  *
+*                                                                    *
+* o Redistributions of source code must retain the above copyright   *
+*   notice, this condition and the following disclaimer.             *
+*                                                                    *
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND             *
+* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,        *
+* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF           *
+* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE           *
+* DISCLAIMED. IN NO EVENT SHALL SEGGER Microcontroller BE LIABLE FOR *
+* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR           *
+* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT  *
+* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;    *
+* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF      *
+* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT          *
+* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE  *
+* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH   *
+* DAMAGE.                                                            *
+*                                                                    *
+**********************************************************************
+*                                                                    *
+*       RTT version: 8.44a                                           *
+*                                                                    *
+**********************************************************************
+
+--------- END-OF-HEADER --------------------------------------------
+File    : Main_RTT_MenuApp.c
+Purpose : Sample application to demonstrate RTT bi-directional functionality
+*/
+
+#define MAIN_C
+
+#include <stdio.h>
+
+#include "SEGGER_RTT.h"
+
+volatile int _Cnt;
+volatile int _Delay;
+
+static char r;
+
+/*********************************************************************
+*
+*       main
+*/
+void main(void) {
+
+  SEGGER_RTT_WriteString(0, "SEGGER Real-Time-Terminal Sample\r\n");
+  SEGGER_RTT_ConfigUpBuffer(0, NULL, NULL, 0, SEGGER_RTT_MODE_NO_BLOCK_SKIP);
+  do {
+    r = SEGGER_RTT_WaitKey();
+    SEGGER_RTT_Write(0, &r, 1);
+    r++;
+  } while (1);
+}
+
+/*************************** End of file ****************************/