Add back missing release testing steps after update

Author: Aljullu

docs/testing/releases/README.md

@@ -1,5 +1,5 @@
+# Releases
 Every release includes specific testing instructions for new features and bug fixes (if applicable). This is a list of the available release testing instruction docs:
-
 -   [2.6.0](./260.md)
     -   [2.6.1](./261.md)
 -   [2.7.0](./270.md)
@@ -71,13 +71,13 @@ 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)
 
 <!-- FEEDBACK -->
----
 
+---
 [We're hiring!](https://woocommerce.com/careers/) Come work with us!
-
 🐞 Found a mistake, or have a suggestion? [Leave feedback about this document here.](https://github.com/woocommerce/woocommerce-gutenberg-products-block/issues/new?assignees=&labels=type%3A+documentation&template=--doc-feedback.md&title=Feedback%20on%20./docs/testing/releases/README.md)
 <!-- /FEEDBACK -->
-