Template:IPA vowels audio/doc

Technical note
Used subtemplates: IPA vowels audio/vowelpair Input options:

The unnamed and named parameters define:
 * 1st= IPA symbol left
 * 2nd= IPA symbol right
 * 3rd= position offset from left side (in %)
 * 4th= position offset from top side (in %)
 * soundfile1 = name of the left soundfile, when different from default (IPAsym-name).
 * soundfile2 = name of the right soundfile, when different from default (IPAsym-name).

Subsequently subtemplate are called, calls IPA vowels audio/soundbox and IPA soundbox, to produce a soundbox + linked symbol per symbol.