pandoc-3.9: test/command/mediawiki_behavior_switches.md

```
% pandoc -f mediawiki -t native
____INDEX____
__NOINDEX__
__noindex__
__FOOBAR__
^D
[ Para
    [ Str "____"
    , SoftBreak
    , Str "__noindex__"
    , SoftBreak
    , Str "__FOOBAR__"
    ]
]
```