Convert the manpage to AsciiDoc

Writing DocBook XML by hand is an awful experience and the tools aren't
much better.  Asciidoctor does it well.  There's no need to worry about
semantics, man(1) just needs to be able to show something at all.

This project's manpage is sadly almost useless right now.

docs/sdtui.1.adoc

@@ -0,0 +1,45 @@
+sdtui(1)
+========
+:doctype: manpage
+:manmanual: sdtui Manual
+:mansource: sdtui {release-version}
+
+Name
+----
+sdtui - StarDict terminal UI
+
+Synopsis
+--------
+*sdtui* [_OPTION_]... [_DICTIONARY_.ifo]...
+
+Description
+-----------
+*sdtui* is a StarDict dictionary viewer custom tailored for viewing translation
+dictionaries, using a simple curses-based terminal UI.
+
+The program expects to find on its command line the path to a dictionary's
+_.ifo_ file, which contains further information required to load the dictionary.
+
+Some options as well as dictionaries to load on start-up by default can be
+specified in a configuration file.  See the README for an example.
+
+// FIXME: the README isn't even installed, so this manual isn't very useful
+
+Options
+-------
+*-h*, *--help*::
+	Display a help message and exit.
+
+*-V*, *--version*::
+	Output version information and exit.
+
+Files
+-----
+_~/.config/sdtui/sdtui.conf_::
+	The configuration file, in which you can configure some settings, terminal
+	colours and the set of dictionaries to be loaded automatically on start-up.
+
+Reporting bugs
+--------------
+Use https://git.janouch.name/p/sdtui to report bugs, request features,
+or submit pull requests.