docs: Fix a few typos

[timgates42]

There are small typos in:

• src/maya/core.py

Fixes:

• Should read preferred rather than prefered.
• Should read ambiguous rather than ambigous.

Semi-automated pull request generated by https://github.com/timgates42/meticulous/blob/master/docs/NOTE.md

[kennethreitz]

thanks!