#2759 windows: Missing documentation for various terminals (gnuplot>=6.0.0)

[theozh]

It seems from gnuplot 6.0.0 on the documentation for various terminals is missing.
If there is documentation for a terminal which I don't have installed, that would be ok,
but if I have terminals installed for which I don't get documenation is very unfortunate.
Most of the documentation was still available for gnuplot 5.x

Checked for Windows 10, gnuplot 6.0.0, 6.02 (from gp602-win64-mingw.7z)

My output for set term

Available terminal types:
cairolatex  LaTeX picture environment using graphicx package and Cairo backend
    canvas  HTML Canvas object
       cgm  Computer Graphics Metafile
   context  ConTeXt with MetaFun (for PDF documents)
   domterm  DomTerm terminal emulator with embedded SVG
      dumb  ascii art for anything that prints text
       dxf  dxf-file for AutoCad (default size 120x80)
       emf  Enhanced Metafile format
  epscairo  eps terminal based on cairo
  epslatex  LaTeX picture environment using graphicx package
       fig  FIG graphics language V3.2 for XFIG graphics editor
       gif  GIF images using libgd and TrueType fonts
      hpgl  HP7475 and relatives [number of pens] [eject]
      jpeg  JPEG images using libgd and TrueType fonts
kittycairo  kitty in-terminal graphics using cairo
   kittygd  kitty in-terminal graphics using libgd
       lua  Lua generic terminal driver
      pcl5  PCL5e/PCL5c printers using HP-GL/2
  pdfcairo  pdf terminal based on cairo
    pict2e  LaTeX2e picture environment
       png  PNG images using libgd and TrueType fonts
  pngcairo  png terminal based on cairo
postscript  PostScript graphics, including EPSF embedded files (*.eps)
   pslatex  LaTeX picture environment with PostScript \specials
     pstex  plain TeX with PostScript \specials
  pstricks  LaTeX picture environment with PSTricks macros
        qt  Qt cross-platform interactive terminal
   sixelgd  sixel using libgd and TrueType fonts
       svg  W3C Scalable Vector Graphics
   texdraw  LaTeX texdraw environment
      tikz  TeX TikZ graphics macros via the lua script driver
  tkcanvas  Tk canvas widget
   unknown  Unknown terminal type - not a plotting device
      webp  single frame or animation using cairo, pango, and libwebp
   windows  Microsoft Windows
       wxt  wxWidgets cross-platform interactive terminal

My output for help term.

windows 
canvas 
cgm 
dumb 
dxf 
emf 
fig 
hpgl 
pcl5 
epslatex 
pslatex and pstex 
postscript 
svg 
domterm 
tkcanvas 
pict2e 
pstricks 
texdraw 
context 
latex 

So, the difference, i.e. missing documentation for:
cairolatex, epscairo, gif, jpeg, kittycairo, kittygd, latex, lua, pdfcairo, png, pngcairo, qt, sixelgd, tikz, unknown, webp, wxt