added 'custom envirnoment' example

documents/custom-environment/Makefile

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+SOURCE = custom-environment
+make:
+	pdflatex $(SOURCE).tex -output-format=pdf
+	make clean
+
+clean:
+	rm -rf  $(TARGET) *.class *.html *.log *.aux *.out

documents/custom-environment/custom-environment.tex

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+\documentclass[a4paper]{scrartcl}
+\usepackage{blindtext}
+
+\newcounter{examplecounter}
+\renewcommand{\theexamplecounter}{\arabic{examplecounter}}
+\newenvironment{Beispiel}[1][]{%
+\goodbreak%
+\refstepcounter{examplecounter}%
+\begin{list}{}{\setlength{\rightmargin}{\leftmargin}}%
+\item[{\textbf{Beispiel~\theexamplecounter:}}]#1\par\nobreak}{%
+\end{list}}
+
+\begin{document}
+Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla quam 
+elit, vestibulum nec facilisis at, condimentum id enim. Sed iaculis 
+lacinia quam, vel accumsan eros tempor in. Integer ipsum metus, 
+accumsan sit amet commodo a, egestas vitae sem. Mauris ut orci ut 
+dolor viverra convallis nec a erat. Aenean consequat elit vel eros 
+fermentum vestibulum id at ipsum. In vitae orci mauris, et rhoncus 
+odio. Pellentesque habitant morbi tristique senectus et netus et 
+malesuada fames ac turpis egestas.
+
+\blindtext[4]
+
+\begin{Beispiel}[A title]
+\begin{tabular}{ccc}
+    1 & 2 & 3\\
+    4 & 5 & 6\\
+    7 & 8 & 9
+  \end{tabular}
+\end{Beispiel}
+\end{document}

tikz/tax-revenue-de-2012-09-piechart/Readme.md

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+TODO: doesn't compile right now