Fix #8 ; add additional links to original Wndchrm
Fix #8 ; add additional links to original Wndchrm

More links were added to the original Wndchrm software project, a new
README.md section heading was added to contain them, and internal links
were modified. Oh, and one typo was fixed.

kjarosz/new_cuda_udat,kjarosz/Cuda-Wndchrm,kjarosz/Cuda-Wndchrm,kjarosz/new_cuda_udat