readme: update.

README.md

@@ -1,5 +1,5 @@
 # stm32flash-lib
-Java based library to talk to stm32 UART bootloader following [AN3155](https://www.st.com/resource/en/application_note/cd00264342.pdf) protocol, and [AN2606](https://www.st.com/resource/en/application_note/cd00167594.pdf) notes.
+Java based library helping to talk to stm32 UART bootloader following [AN3155](https://www.st.com/resource/en/application_note/cd00264342.pdf) protocol, and [AN2606](https://www.st.com/resource/en/application_note/cd00167594.pdf) notes.
 
 See [stm32flash-util](https://github.com/grevaillot/stm32flash-util) for usage.
 
@@ -8,12 +8,14 @@ See [stm32flash-util](https://github.com/grevaillot/stm32flash-util) for usage.
   - Make sure that your UART interface is configured as specified in AN3155 - with proper parity setting.
   - Device table is taken from [stm32flash](https://sourceforge.net/projects/stm32flash/) project.
   - Currently, only binary firmware files are supported.
+  - Currently, devices with multiple flash pages sizes are not supported.
 
 ## Tested Devices:
 
-Project has not been tested against much devices, basically only F0, F1, L0, L1 devices, specifically (non exhaustive list):
+Project has not been tested against much devices, basically only F0, F1, L0, L1 and G4 devices, specifically (non exhaustive list):
 
   - stm32f042x4, stm32f030xC, stm32f091xC
   - stm32f100x6, stm32f103x6
   - stm32l151xC
   - stm32l072xC
+  - stm32g474xE