add the Czech Markup module

MarkupNP marks s, clit and prep, since in Czech these are alternative
surface forms of a pronoun chosen by context, as in MarkupRomance.
The nominative clitic is left alone: it is the pro-drop subject, empty
for every personal pronoun, so marking it up gave "<b> </b> je starý".

Inherit MarkupCze in LangCze, as LangFin does; stringMark is excluded
because abstract Lang already excludes it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/czech/LangCze.gf

@@ -1,10 +1,11 @@
 --# -path=.:../abstract:../common:../api
 
-concrete LangCze of Lang = 
+concrete LangCze of Lang =
   GrammarCze,
   LexiconCze
 --  ,ConstructionCze
 --  ,DocumentationCze --# notpresent
+  ,MarkupCze - [stringMark]
   ** {
 
 }