Precise wake word training

[krisgesling]

Bring info from Wiki into primary docs.
https://github.com/MycroftAI/mycroft-precise/wiki/Training-your-own-wake-word#how-to-train-your-own-wake-word

Some learnings from users include:

• Own wake word never detected despite precise-test accuracy of 100% mycroft-precise#94

[TheCedarPrince]

Hey @krisgesling - referencing my issue here as I am in the process of figuring out problems which exist with creating my own wake word using Mycroft-Precise and testing it on the Pi. Hopefully I will be able to close my issue soon and we can add what we find out to the docs.

MycroftAI/mycroft-precise#90

[krisgesling]

Awesome, thanks :)