* Fix missing link to MinGW website.
* Add link to library dependency section in introduction.
* Add "Known Issues" section to document known build issues.
* Change command blocks from using ``` to delineate block and use indentation
instead. The ``` method seems to be broken on Doxygen 1.8.9.1 used by the
autobuilder. It also removes the line numbering which did not make sense
for commands that spanned multiple lines.
* Add compiling.md with most of the important information from the plain
text versions of platform specific compiling files.
* Remove the old plain text compiling files and folder.