'but how does one 'Link Text'?'
Thisrefers to the text you want your link to appear as so rather than, for example :
if you want it to appear as : a charming print of Bonarparte, in his Green Linnet costume
then you type (or paste) that text in the link text box and your link will appear as :
a charming print of Bonarparte, in his Green Linnet costume
Do check if the link works before posting. In this case the link you posted above goes to a 404.