update readme

README.org

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 * scrtest1
+** what is this
+Testing the LCD screen on the [[https://www.st.com/en/evaluation-tools/32f429idiscovery.html][STM32f429i-DISC1]] discovery board.
+** sources
+*** Drivers/BSP/STM32F429I-Discovery
+[[https://github.com/STMicroelectronics/32f429idiscovery-bsp/releases/tag/v2.1.8]]
 ** get working for development
 #+begin_src bash
   git clone https://git.therats.win/jazz/scrtest1.git