Remove private GitHub repository contributions/istqb_latex

.gitmodules

@@ -13,6 +13,3 @@
 [submodule "contributions/MarkX"]
 	path = contributions/MarkX
 	url = https://github.com/lostenderman/MarkX
-[submodule "contributions/istqb_latex"]
-	path = contributions/istqb_latex
-	url = https://github.com/danopolan/istqb_latex.git

contributions/README.md

@@ -3,15 +3,13 @@ been contributed to the Markdown package:
 
 - [book-templates][] from [xvrabcov][]: Open-source Markdown LaTeX themes for typesetting books and marketing colaterals
 - [doctoral-thesis][] from [witiko][]: A doctoral thesis written using the Markdown package
-- [istbq_latex][] from [danopolan][]: Document templates for the International Software Testing Qualifications Board (ISTBQ) syllabi
 - [MarkX][] from [lostenderman][]: A tool for converting XML examples from CommonMark to test files used in the Markdown package
   - For more information, see also [the bachelor's thesis][thesis-r7z7l] of [lostenderman][].
 - [pandoc-to-markdown][] from [drehak][]: A proof-of-concept that shows how Pandoc can be integrated with the Markdown package
   - For more information, see also [the bachelor's thesis][thesis-umhg5] of [drehak][].
 
  [book-templates]: https://github.com/xvrabcov/md-templates
  [doctoral-thesis]: https://github.com/witiko/doctoral-thesis
- [istbq_latex]: https://github.com/danopolan/istqb_latex
  [MarkX]: https://github.com/lostenderman/MarkX
  [pandoc-to-markdown]: https://github.com/drehak/pandoc-to-markdown
 
@@ -25,7 +23,6 @@ package but cannot be directly included as Git submodules:
 
  [l4070]: https://gitlab.com/l4070
 
- [danopolan]: https://github.com/danopolan
  [drehak]: https://github.com/drehak
  [lostenderman]: https://github.com/lostenderman
  [TeXhackse]: https://github.com/TeXhackse