Support Float child

[Infrared1029]

Right now doing:

import htpy

htpy.div[1.5]

errors with:

TypeError: 1.5 is not a valid child element

Is there any reason float is not supported?

[Infrared1029]

Going through the tests, it is a deliberate decision I guess as the library directly tests for that case, curious to know why tho, feels convenient to just throw a float without having to do a str(...), given that int is already supported