Clarify orientation requirements for base stations

[jonnew]

The following text

https://github.com/open-ephys/bonsai-onix1/blob/cdc835e882bc61d5f3121f3d56020401e5c298bd/OpenEphys.Onix1/TS4231V1PositionData.cs#L27C60-L27C80

says the following:

/// <item><description>The base stations are pointed in the same direction.</description></item>

This should changed to:

/// <item><description>The base stations are in the same 3D orientation at an arbitrary 3D offset.</description></item>

[cjsha]

This is the most extensive explanation of lighthouse positioning/orienting I've seen. Are there are any more details? I'm going to port this information to onix hardware docs per open-ephys/onix-docs#18