treat doc source as utf-8

docs/changelog.txt

@@ -63,6 +63,7 @@ Template for new versions:
 - wherever units are listed in DFHack tools, properties like "agitated" or (-trained-) are now shown
 
 ## Documentation
+- UTF-8 text in tool docs is now properly displayed in-game in `gui/launcher` (assuming that it can be converted to cp-437)
 
 ## API
 

library/lua/helpdb.lua

@@ -138,6 +138,7 @@ local function update_entry(entry, iterator, opts)
     local tags_found, short_help_found = false, opts.skip_short_help
     local in_tags, in_short_help = false, false
     for line in iterator do
+        line = dfhack.utf2df(line)
         if not short_help_found and first_line_is_short_help then
             line = line:trim()
             local _,_,text = line:find('^'..first_line_is_short_help..'%s*(.*)')