docs: note about Symfony 6.4 LTS

README.md

@@ -1,8 +1,8 @@
 # MicroSymfony 🎶
 
-## Introduction 🖋
+## Introduction 🖋 
 
-MicroSymfony is a Symfony application skeleton on steroids, ready to use.
+MicroSymfony is a Symfony 7.0 application skeleton on steroids, ready to use.
 
 I have made a long blog post explaining all it contains; it will be the reference
 for documentation. 
@@ -13,6 +13,9 @@ I'll update it when needed:
 So this blog post is the official documentation.
 This readme is a teaser of what MicroSymfony contains.
 
+If you you go back to the last Symfony 6.4 LTS versionn, in your `composer.json file`,
+replace all occurences of `7.0` by `6.4` and run `composer up`.  
+
 
 ## Demo 🌈