Address various issues spotted by @HuwCampbell:

- add note on `PSReadline` settings in order to get tooltips
- do not trim dashes in option names
- fix command index if we are completing an "empty word"
- add space if we are trying to complete a full word

Author: ShrykeWindgrace

README.md

@@ -834,6 +834,10 @@ completion system:
    PS> foo --pwsh-completion-script (Get-Command foo).Source >> _foo.ps1
    PS> . _foo.ps1
    ```
+   You might want to add `Set-PSReadlineKeyHandler -Key Tab -Function MenuComplete`
+   to your powershell/pwsh profile in order to get better experience
+   with completion tooltips.
+
    Note for windows users - this will generate completion script for `foo.exe`,
    which is not equivalent to `foo` from tab-completion engine's point of view,
    even though from usage point view they are equivalent. You might want to edit

src/Options/Applicative/BashCompletion.hs

@@ -282,19 +282,20 @@ pwshCompletionScript prog progn = unlines
   , ""
   , "    $localCommand += '\"--bash-completion-index\"'"
   , "    if ($wordToComplete.Equals(\"\")) {"
-  , "        $localCommand += '\"0\"'"
+  , "        $localCommand +=  '\"' + $commandAst.CommandElements.Count +'\"'"
   , "    }"
   , "    else {"
   , "        $localCommand += '\"' + $hay.IndexOf($wordToComplete) + '\"'"
   , "    }"
   , "    $inp = & '" ++ prog ++ "' @localCommand"
   , "    [CompletionResult[]]$out = @()"
+  , "    [string]$suffix =  if ($inp.Count -eq 1) {' '} else {\"\"}"
   , "    foreach ($item in $inp) {"
   , "        $spl = $item.Split(\"`t\")"
   , "        $show = $spl[0]"
   , "        $tooltip = if ($spl.Length -eq 1) { $spl[0] } else { $spl[1] }"
   , "        $crt = if ($show.StartsWith('-')) { [CompletionResultType]::ParameterName } else { [CompletionResultType]::ParameterValue }"
-  , "        $out += [CompletionResult]::new($show, $show.Trim('-'), $crt, $tooltip)"
+  , "        $out += [CompletionResult]::new($show + $suffix, $show, $crt, $tooltip)"
   , "    }"
   , "    $out"
   , "}"