Source codes examples to ease doc reading

[DjPoke]

Hi,
It could be very nice to add some BBCBASIC or ez80asm example files for each part of the docs.
(If you do not have time for this, i can help for some stuffs, but not for the things i'm not shure)

[DjPoke]

And add a link to the last updated mos_api.inc could be nice too.