Add link to WC Blocks 7.6.1 testing steps

Author: Aljullu

docs/testing/releases/README.md

@@ -71,6 +71,7 @@ Every release includes specific testing instructions for new features and bug fi
     -   [7.4.2](./742.md)
 -   [7.5.0](./750.md)
 -   [7.6.0](./760.md)
+-   [7.6.1](./761.md)
 -   [7.7.0](./770.md)
 -   [7.8.0](./780.md)
 -   [7.8.1](./781.md)