Update README
Squashed 'sources/csprng/' content from commit 0230b0b

git-subtree-dir: sources/csprng
git-subtree-split: 0230b0be31d72c9adf1514067be99d6b5da2b539
Merge commit '61e924e28246c9e2b66fbdeadbb7c940cc7f9cb7' as 'sources/csprng'
Use CSPRNG library for createSalt()