Add support for a linkName frontmatter attribute that controls the alias
text inserted during wiki link autocomplete. The precedence order is:
linkName > displayName > page name.
This allows users to have separate link text from display name. For example,
a page for "Randy Mario Poffo" can have linkName: "Randy Savage" and
displayName: "Macho Man", resulting in [[Randy Mario Poffo|Randy Savage]]
when selected from autocomplete.