bug#36529: Docs say font-lock-mode should be on by default

[積丹尼 Dan Jacobson]

(info "(emacs) Font Lock") says

   Font Lock mode is enabled by default.

$ emacs -q --no-site-file
C-h v font-lock-mode

font-lock-mode is a variable defined in ‘font-core.el’.
Its value is nil

  Automatically becomes buffer-local when set.

Documentation:
Non-nil if Font-Lock mode is enabled.

emacs-version "26.1"

$ apt-cache policy emacs
emacs:
  Installed: 1:26.1+1-3.2
  Candidate: 1:26.1+1-3.2
  Version table:
 *** 1:26.1+1-3.2 500
        500 http://opensource.nchc.org.tw/debian unstable/main i386 Packages
        100 /var/lib/dpkg/status

P.S.,
global-font-lock-mode is a variable defined in ‘font-core.el’.
Its value is nil