I used micropython, because I haven't used it for a project yet and I was shocked how well it worked for this. There are many tutorials on how to use Thonny with an ESP32, and I found it to be much quicker than doing this in Arduino/ C++. The main files...
Now we need to add a file that is missing from the tts repositories. Fortunately Google themselves make it available but it needs some modifications to make it work with the Raspi port. You can find the file at https://android.googlesource.com/platform/external/svox/+/9b08cc440f25c4722ca112642be87053fc47f918/pico/tts/com_svox_picottsengine.cpp...