doc: Add myself as a co-author.

Dependencies

• [2] CPQQFQMZ doc: Reintegrate the intro by Visser & Dolstra from `manual.html'.
• [*] 5AKAE3R6 start of hydra manual

Change contents

• edit in doc/manual/manual.xml at line 44
  [2.10489]

  [4.894]
  + <author>

  + <personname>

  + <firstname>Ludovic</firstname>

  + <surname>Courtès</surname>

  + </personname>

  + <contrib>Author</contrib>

  + </author>