modified README

Author: linjing-lab

README.md

@@ -13,7 +13,7 @@
 |[Insertion Sort](./docs/Insertionsort.md)|$\Omega(n)$|$\Theta(n^2)$|$O(n^2)$|$O(1)$|
 |[Selection Sort](./docs/Selectionsort.md)|$\Omega(n^2)$|$\Theta(n^2)$|$O(n^2)$|$O(1)$|
 |Tree Sort|$\Omega(n \log(n))$|$\Theta(n \log(n))$|$O(n^2)$|$O(n)$|
-|Shell Sort|$\Omega(n \log (n))$|$\Theta(n(\log (n))^2)$|$O(n(\log (n))^2)$|$O(1)$|
+|[Shell Sort](./docs/Shellsort.md)|$\Omega(n \log (n))$|$\Theta(n(\log (n))^2)$|$O(n(\log (n))^2)$|$O(1)$|
 |[Bucket Sort](./docs/Bucketsort.md)|$\Omega(n + k)$|$\Theta(n + k)$|$O(n^2)$|$O(n)$|
 |Radix Sort|$\Omega(nk)$|$\Theta(nk)$|$O(nk)$|$O(n+k)$|
 |[Counting Sort](./docs/Countingsort.md)|$\Omega(n + k)$|$\Theta(n + k)$|$O(n + k)$|$O(k)$|