[DOC] Highlight important info in README.md

Author: ALABSTM

README.md

@@ -2,9 +2,8 @@
 
 ![latest tag](https://img.shields.io/github/v/tag/STMicroelectronics/STM32CubeU5.svg?color=brightgreen)
 
-## Important note
-
-This repository has been created using the `git submodule` command. Please refer to the ["How to use"](README.md#how-to-use) section for more details.
+> [!IMPORTANT]
+> This repository has been created using the `git submodule` command. Please refer to the ["How to use"](README.md#how-to-use) section for more details.
 
 ## Overview
 
@@ -21,21 +20,24 @@ This repository has been created using the `git submodule` command. Please refer
 
 The **STM32CubeU5 MCU Package** projects are directly running on the STM32U5 series boards. You can find in each Projects/*Board name* directories a set of software projects (Applications, Demonstration, Examples).
 
-## Some middleware libraries and projects are unavailable in this repository
-
-In this repository, the middleware libraries listed below **along with** [this](Projects/README.md#list-of-unavailable-projects) list of projects (demos, applications, and examples) using them, are **not available** as they (the middleware libraries) are subject to some restrictive license terms requiring the user's approval via a "click thru" procedure.
-* `./Middlewares/ST/SE_STSAFEA_API`
-* `./Middlewares/ST/STSAFE_A1xx`
-
-If needed, they can be found inside the full firmware package available on our website `st.com` and downloadable from [here](https://www.st.com/content/st_com/en/products/embedded-software/mcu-mpu-embedded-software/stm32-embedded-software/stm32cube-mcu-mpu-packages/stm32cubeu5.html#get-software). You will be prompted to login or to register in case you have no account.
+> [!NOTE]
+> ## Some middleware libraries and projects are unavailable in this repository
+>
+> In this repository, the middleware libraries listed below **along with** [this](Projects/README.md#list-of-unavailable-projects) list of projects (demos, 
+> applications, and examples) using them, are **not available** as they (the middleware libraries) are subject to some restrictive license terms requiring the user's 
+> approval via a "click thru" procedure.
+> * `./Middlewares/ST/SE_STSAFEA_API`
+> * `./Middlewares/ST/STSAFE_A1xx`
+> 
+> If needed, they can be found inside the full firmware package available on our website `st.com` and downloadable from [here](https://www.st.com/content/st_com/en/products/embedded-software/mcu-mpu-embedded-software/stm32-embedded-software/stm32cube-mcu-mpu-packages/stm32cubeu5.html#get-software). You will be prompted to login or to register in case you have no account.
 
 ## Release note
 
 Details about the content of this release are available in the release note [here](https://htmlpreview.github.io/?https://github.com/STMicroelectronics/STM32CubeU5/blob/master/Release_Notes.html).
 
 ## How to use
 
-This repository has been created using the `git submodule` command. Please check the instructions below for proper use. Please check also the [notes](README.md#notes) at the end of this section for further information.
+This repository has been created using the `git submodule` command. Please check the instructions below for proper use. Please check also **the notes at the end of this section** for further information.
 
 1. To **clone** this repository along with the linked submodules, option `--recursive` has to be specified as shown below.
 
@@ -62,11 +64,10 @@ git checkout vX.Y.Z # Specify the targeted vX.Y.Z version
 git clone --recursive  --depth 1 --branch vX.Y.Z https://github.com/STMicroelectronics/STM32CubeU5.git
 ```
 
-#### Notes
-
-* The latest version of this firmware available on GitHub may be **ahead** of the one available on [st.com](https://www.st.com/en/microcontrollers-microprocessors/stm32-32-bit-arm-cortex-mcus.html) or via [STM32CubeMX](https://www.st.com/en/development-tools/stm32cubemx.html). This is due to the **rolling release** process deployed on GitHub. Please refer to [this](https://github.com/STMicroelectronics/STM32Cube_MCU_Overall_Offer/discussions/21) post for more details.
-* Option `--depth 1` specified in instruction (4) above is **not** mandatory. It may be useful to skip downloading all previous commits up to the one corresponding to the targeted version.
-* If GitHub "Download ZIP" option is used instead of the `git clone` command, then the different submodules have to be collected and added **manually**.
+> [!NOTE]
+> * The latest version of this firmware available on GitHub may be **ahead** of the one available on [st.com](https://www.st.com/en/microcontrollers-microprocessors/stm32-32-bit-arm-cortex-mcus.html) or via [STM32CubeMX](https://www.st.com/en/development-tools/stm32cubemx.html). This is due to the **rolling release** process deployed on GitHub. Please refer to [this](https://github.com/STMicroelectronics/STM32Cube_MCU_Overall_Offer/discussions/21) post for more details.
+> * Option `--depth 1` specified in instruction (4) above is **not** mandatory. It may be useful to skip downloading all previous commits up to the one corresponding to the targeted version.
+> * If GitHub "Download ZIP" option is used instead of the `git clone` command, then the different submodules have to be collected and added **manually**.
 
 ## Boards available
   * STM32U5