Fix formatting

free-programming-books.md

@@ -1701,9 +1701,9 @@ See also [LaTeX](#latex)
 
 
 ###VHDL
-*[VHDL Tutorial](http://www.seas.upenn.edu/~ese171/vhdl/vhdl_primer.html)
+* [VHDL Tutorial](http://www.seas.upenn.edu/~ese171/vhdl/vhdl_primer.html)
-*[VHDL Tutorial](http://hep.uchicago.edu/~tangjian/SVT_sub/FTK_ATLAS/AUX/vhdl-tutorial.pdf) - Peter J. Ashenden
+* [VHDL Tutorial](http://hep.uchicago.edu/~tangjian/SVT_sub/FTK_ATLAS/AUX/vhdl-tutorial.pdf) - Peter J. Ashenden
-*[VHDL Tutorial: Learn By Example](http://esd.cs.ucr.edu/labs/tutorial/)
+* [VHDL Tutorial: Learn By Example](http://esd.cs.ucr.edu/labs/tutorial/)
 
 
 ###Vim