The "link" type should accept also a plain url

[buseca]

T̶h̶e̶ u̶s̶e̶r̶ w̶i̶l̶l̶ b̶e̶ a̶b̶l̶e̶ t̶o̶ u̶s̶e̶ t̶h̶e̶ "r̶e̶n̶a̶m̶e̶" s̶e̶t̶t̶i̶n̶g̶ t̶o̶ g̶i̶v̶e̶ i̶t̶ a̶ p̶r̶o̶p̶e̶r̶ l̶a̶b̶e̶l̶.

By inserting the sole URL, we use the default label which is "Open Link"

[buseca]

@dbertella I updated the specs for the link, adding a default label