[Signals] Typo in list of signals

[qk7b]

In the list of signals, there are some typos:

• HighBeamsSts instead of HighBeamSts
• LowBeamsSts instead of LowBeamSts
• HeadLightsSts instead of HeadLightSts

[qk7b]

I'll add all the signals for the platform, even those which are not available by default.

[qk7b]

See #44

[LeGuit]

Au final, il y a un 's' ou pas de 's' ? @quentin7b

[qk7b]

The documentation on GitHub is the truth. See https://github.com/xee-lab/xee-api-docs/blob/master/api/api/v3/cars/signals_list.md