A Tiny Cython Experiment

1. create hi.py
```
import platform
print("Hi!")
print(f"Python{platform.python_version()}")
```

2. compile and run it
```
cython --embed -3 -o hi.c hi.py
gcc -o hi.o -c hi.c `python3-config --cflags` -fPIC
gcc -o hi hi.o `python3-config --ldflags`
./hi
```