Remove trailing spaces

The commands

find . -type f -name '*.md' -exec sed --in-place 's/[[:space:]]\+$//' {} \+

and

find . -type f -name '*.tex' -exec sed --in-place 's/[[:space:]]\+$//' {} \+

were used to do so.

tikz/bias-variance/bias-variance.tex

@@ -52,6 +52,6 @@
       \addplot[domain=0:2, red, very thick,samples=500] {3*(x-2)*x+3.8};
       \addlegendentry{training error}
       \addlegendentry{validation}
-    \end{axis} 
+    \end{axis}
 \end{tikzpicture}
 \end{document}