[MacPorts] #47315: simplify Makefile for doc

[MacPorts]

#47315: simplify Makefile for doc
--------------------------+----------------------
  Reporter:  lists@…      |      Owner:  markd@…
      Type:  enhancement  |     Status:  new
  Priority:  Normal       |  Milestone:
 Component:  guide        |    Version:  2.3.3
Resolution:               |   Keywords:  haspatch
      Port:               |
--------------------------+----------------------

Comment (by lists@…):

 fwiw, tested on OS X but not tested on Linux

-- 
Ticket URL: <https://trac.macports.org/ticket/47315#comment:1>
MacPorts <https://www.macports.org/>
Ports system for OS X