add mixbox for python

python/examples/hello.py

@@ -0,0 +1,9 @@
+import mixbox
+
+rgb1 = (0, 33, 133)  # blue
+rgb2 = (252, 211, 0) # yellow
+t = 0.5              # mixing ratio
+
+rgb_mix = mixbox.lerp(rgb1, rgb2, t)
+
+print(rgb_mix)