Non expressive variable name on transformer.py

[joaoCeilandia]

Description of Problem:
Issue: On file ...\utils\tensorflow\transformer.py in the line 566 has a variable with a non expressive name i.

Overview of the Solution:
Change the name from i to something more expressive.

[sara-tagger]

Thanks for submitting this feature request 🚀 @melindaloubser1 will get back to you about it soon! ✨

[indam23]

rasa/rasa/utils/tensorflow/transformer.py

Lines 565 to 567 in c6142eb

	def _get_angles(self) -> np.ndarray:
	i = np.arange(self.units)[np.newaxis, :]
	return 1 / np.power(10000, (2 * (i // 2)) / np.float32(self.units))

What would you change it to?

[indam23]

Since you already opened a PR to fix #8453, you could add a fix there for this too