doxygen: disable markdown support

The intendation used in hidapi makes most of the comments get
interpreted as codeblocks which breaks most functions of Doxygen.

Author: z3ntu

doxygen/Doxyfile

@@ -313,7 +313,7 @@ EXTENSION_MAPPING      =
 # case of backward compatibilities issues.
 # The default value is: YES.
 
-MARKDOWN_SUPPORT       = YES
+MARKDOWN_SUPPORT       = NO
 
 # When the TOC_INCLUDE_HEADINGS tag is set to a non-zero value, all headings up
 # to that level are automatically included in the table of contents, even if