SG-32814 Fixup supported versions (#82)

Author: julien-lang

README.md

@@ -1,6 +1,6 @@
 # Toolkit Engine for Houdini
 
-![Supported Houdini versions: 19.5 - 20.5](https://img.shields.io/badge/Houdini-20.5_|_20.0_|_19.5-blue?logo=houdini&logoColor=f5f5f5 "Support Maya versions")
+![Supported Houdini versions: 19.5 - 20.5](https://img.shields.io/badge/Houdini-19.5_--_20.5-blue?logo=houdini&logoColor=f5f5f5 "Support Maya versions")
 [![Supported VFX Platform: 2022 - 2025](https://img.shields.io/badge/VFX_Platform-2025_|_2024_|_2023_|_2022-blue)](http://www.vfxplatform.com/ "Supported VFX Platform")
 [![Supported Python versions: 3.9 - 3.11](https://img.shields.io/badge/Python-3.11_|_3.10_|_3.9-blue?logo=python&logoColor=f5f5f5)](https://www.python.org/ "Supported Python versions")
 

engine.py

@@ -25,7 +25,7 @@
 
 # Houdini versions compatibility constants
 VERSION_OLDEST_COMPATIBLE = (18, 5)
-VERSION_OLDEST_SUPPORTED = (19, 0)
+VERSION_OLDEST_SUPPORTED = (19, 5)
 VERSION_NEWEST_SUPPORTED = (20, 5)
 # Caution: make sure compatibility_dialog_min_version default value in info.yml
 # is equal to VERSION_NEWEST_SUPPORTED