Wrong link for bbcode_steam in MANUAL.txt

[refashioned]

pandoc/MANUAL.txt

Lines 307 to 312 in cb8739f

	- `bbcode` [BBCode]
	- `bbcode_fluxbb` [BBCode (FluxBB)]
	- `bbcode_phpbb` [BBCode (phpBB)]
	- `bbcode_steam` [BBCode (Hubzilla)]
	- `bbcode_hubzilla` [BBCode (Hubzilla)]
	- `bbcode_xenforo` [BBCode (xenForo)]

The link for bbcode_steam is a copy of [BBCode (Hubzilla)]. It should be [BBCode (Steam)].

[jgm]

thx!