typo error for SVD

[kyhhdm]

An error was reported found in the front page (https://dsc-spidal.github.io/harp/):
"It says somewhere single value decomposition but it should be singular value decomposition."

I found two places :
1). anchor text down in the bottom under the column of "Harp-DAAL"
2). text in the tile image of svd algorithm

[SabraO]

fixed 1) @ 24e1f4f