Fix the inconsistent Dutch translation of 'voltage'
Voltage was translated as both 'voltage' and 'spanning'. The latter is the preferred term in Dutch. See, for example, the Dutch wikipedia page: https://nl.wikipedia.org/wiki/Elektrische_spanning
Voltage was translated as both 'voltage' and 'spanning'. The latter is the preferred term in Dutch. See, for example, the Dutch wikipedia page: https://nl.wikipedia.org/wiki/Elektrische_spanning