style(README): Add admonitions (note)

Author: ebouchut

README.md

@@ -565,9 +565,9 @@ where:
 - `.copy` shows the copy-to-clipboard button when present (hidden otherwise)
 - `title=“title of this code block”` adds a title to the code (none when absent)
 
-Do note that:
-- There is a space before **and** after the opening curly brace ` { `.
-- There is space before the closing curly brace `}`.
+> [!NOTE]
+> - There is a space **before and after** the **opening** curly brace ` { `.
+> - There is space **before** the **closing** curly brace `}`.
 
 
 [Source](https://squidfunk.github.io/mkdocs-material/reference/code-blocks/?h=copy+clipboard#code-copy-button)
@@ -615,7 +615,10 @@ The website uses the Markdown page of the glossary.
 ### Add a Package
 
 > [!NOTE]
-> In this section, the terms Python **package** and **dependency** refer to the same thing.
+> In this section:
+> 
+> - the terms Python **package** and **dependency** refer to the same thing.
+> -  `XXX` denotes the name of the package to add
 
 - **Create** a feature **branch** (aka. topic branch)
   ```shell