Add links to README requirements

README.md

@@ -6,9 +6,12 @@ An experiment in automatic karaoke timing.
 
 ## Requirements
 
-- MKVToolnix (at least the CLI utils)
-- FFmpeg
-- Python >= 3.8
+- [FFmpeg](https://ffmpeg.org/)
+- [Python >= 3.8](https://www.python.org/) (tested up to latest 3.11 version)
+
+Optional :
+
+- [MKVToolnix](https://mkvtoolnix.download/) (at least the CLI utils) : required for the preprocessing scripts
 
 All other python modules can be installed directly through PIP, see next section.
 
@@ -16,8 +19,11 @@ All other python modules can be installed directly through PIP, see next section
 
 Using a virtual environment is strongly recommended (but not mandatory if you know what you're doing) :
 ```bash
-python -m venv env     # create the virtual environment, do it once
-source env/bin/activate # use the virtual environement
+# create the virtual environment, do it once
+python -m venv env
+
+# activate the virtual environement
+source env/bin/activate
 
 # To exit the virtual environment
 deactivate