Updated the docstrings for ViewableElement
Updated the docstrings for ViewableElement

vascotenner/holoviews,ioam/holoviews,basnijholt/holoviews,mjabri/holoviews,mjabri/holoviews,vascotenner/holoviews,basnijholt/holoviews,vascotenner/holoviews,ioam/holoviews,mjabri/holoviews,ioam/holoviews,basnijholt/holoviews