Lack of command highlighting in texinfo-mode

[Christopher Dimech <dimech@gmx.com>]

What code takes care of texinfo highlighting for the following
Contents in @anchor do get highlighted, but there is no highlighting
for most of the others by default.  This makes code very difficult
to introspect.

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Colourising inside @anchor
  @anchor{bibl-lin-moschetti-ritzwoller-2008}

Colourising inside @sc
  @sc{Lin, Fan Chi}

Colourising inside @strong
  @strong{Surface wave tomography of the western United States}

Colourising inside @uref
  @uref{http://ciei.colorado.edu/pubs/2008gji.pdf,,[@sc{Complete Article}]}