Add migration guides

Author: louismaximepiton

site/src/content/docs/getting-started/migration-from-boosted.mdx

@@ -43,6 +43,8 @@ From now on, OUDS Web won’t embed Bootstrap elements that are not part of Oran
 
 - <span class="tag tag-small rounded-none tag-negative">Breaking</span> jQuery support has been removed from the library.
 
+- <span class="tag tag-small rounded-none tag-warning">Warning</span> We don't use PopperJs anymore and we replaced it by Floating UI.
+
 ## Fonts
 
 OUDS Web doesn’t provide Helvetica Neue font files. Instead, it loads the font from a CDN in order to share the cached files between every project using OUDS Web.

site/src/content/docs/getting-started/migration.mdx

@@ -17,6 +17,8 @@ toc: true
 
 - <span class="tag tag-small rounded-none tag-negative">Breaking</span> jQuery support has been removed from the library.
 
+- <span class="tag tag-small rounded-none tag-warning">Warning</span> We don't use PopperJs anymore and we replaced it by Floating UI.
+
 ### Components
 
 #### Footer