man: add a bash-completion scriptlet

Only one for all four games and only static for the time being.

In the long term, we should modify the docgen script to emit the
possible valid command line parameters and their additional options
and thus create separate bash-completion scriptlets for all four
games.

man/bash-completion/chocolate-doom

@@ -0,0 +1,58 @@
+# bash completion for Chocolate Doom                       -*- shell-script -*-
+
+_chocolate_doom()
+{
+    local cur prev words cword
+    _init_completion || return
+
+    case $prev in
+        -config|-extraconfig)
+            _filedir cfg
+            ;;
+        -episode)
+            COMPREPLY=(1 2 3 4)
+            ;;
+        -file|-iwad|-aa|-af|-as|-merge|-nwtmerge)
+            _filedir wad
+            ;;
+        -loadgame)
+            COMPREPLY=(0 1 2 3 4 5)
+            ;;
+        -pack)
+            COMPREPLY=(doom2 tnt plutonia)
+            ;;
+        -skill)
+            COMPREPLY=(1 2 3 4 5)
+            ;;
+        -gameversion)
+            COMPREPLY=(1.9 ultimate final final2 hacx chex)
+            ;;
+        -setmen)
+            COMPREPLY=(dos622 dos71 dosbox)
+            ;;
+        -playdemo|-timedemo)
+            _filedir lmp
+            ;;
+        -deh)
+            _filedir bex deh
+            ;;
+    esac
+
+    if [[ $cur == -* ]]; then
+        COMPREPLY=( $( compgen -W '-1 -2 -3 -aa -af -altdeath -as -autojoin -avg
+        -cdrom -config -connect -deathmatch -dedicated -deh -dehlump -devparm
+        -donut -dumpsubstconfig -dup -episode -extraconfig -extratics -fast
+        -file -fullscreen -gameversion -geometry -grabmouse -height
+        -ignoreversion -iwad -left -loadgame -localsearch -longtics -maxdemo -mb
+        -merge -mmap -newsync -noblit -nocheats -nodeh -nodes -nodraw
+        -nograbmouse -nomonsters -nomouse -nomusic -nonovert -nosfx -nosound
+        -novert -nwtmerge -pack -playdemo -port -privateserver -query -record
+        -respawn -right -search -server -servername -setmem -skill -solo
+        -spechit -statdump -timedemo -timer -turbo -warp -width -window
+        -zonescan -zonezero ' -- "$cur" ) )
+    fi
+} &&
+
+complete -F _chocolate_doom chocolate-doom chocolate-heretic chocolate-hexen chocolate-strife
+
+# ex: ts=4 sw=4 et filetype=sh