chore(expect): update docblock for toContain() to display info on substring check (#15789)

Author: hainenber

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## main
 
+# Chore
+
+- `[expect]` Update docblock for `toContain()` to display info on substring check ([#15789](https://github.com/jestjs/jest/pull/15789))
+
 ## 30.0.5
 
 ### Features

packages/expect/src/types.ts

@@ -209,6 +209,7 @@ export interface Matchers<R extends void | Promise<void>, T = unknown> {
   /**
    * Used when you want to check that an item is in a list.
    * For testing the items in the list, this uses `===`, a strict equality check.
+   * `.toContain` can also check whether a string is a substring of another string.
    */
   toContain(expected: unknown): R;
   /**