docs: add some type info for expect docs

docs/ExpectAPI.md

@@ -203,7 +203,40 @@ expect.extend({
 });
 ```
 
-:::
+:::note
+
+In TypeScript, when using `@types/jest` for example, you can declare the new `toBeWithinRange` matcher in the imported module like this:
+
+```ts title="toBeWithinRange.ts"
+expect.extend({
+  toBeWithinRange(received: number, floor: number, ceiling: number) {
+    // ...
+  },
+});
+declare global {
+  namespace jest {
+    interface Matchers<R> {
+      toBeWithinRange(a: number, b: number): R;
+    }
+  }
+}
+```
+
+If you want to move the typings to a separate file (e.g. `types/jest/index.d.ts`), you may need to an export, e.g.:
+
+```ts
+interface CustomMatchers<R = unknown> {
+  toBeWithinRange(floor: number, ceiling: number): R;
+}
+declare global {
+  namespace jest {
+    interface Expect extends CustomMatchers {}
+    interface Matchers<R> extends CustomMatchers<R> {}
+    interface InverseAsymmetricMatchers extends CustomMatchers {}
+  }
+}
+export {};
+```
 
 #### Async Matchers
 

website/versioned_docs/version-25.x/ExpectAPI.md

@@ -70,6 +70,12 @@ test('numeric ranges', () => {
 _Note_: In TypeScript, when using `@types/jest` for example, you can declare the new `toBeWithinRange` matcher in the imported module like this:
 
 ```ts
+expect.extend({
+  toBeWithinRange(received, floor, ceiling) {
+    // ...
+  },
+});
+
 interface CustomMatchers<R = unknown> {
   toBeWithinRange(floor: number, ceiling: number): R;
 }
@@ -83,6 +89,19 @@ declare global {
 }
 ```
 
+If you want to move the typings to a separate file (e.g. `types/jest/index.d.ts`), you may need to an export, e.g.:
+
+```ts
+declare global {
+  namespace jest {
+    interface Matchers<R> {
+      toBeWithinRange(a: number, b: number): R;
+    }
+  }
+}
+export {};
+```
+
 #### Async Matchers
 
 `expect.extend` also supports async matchers. Async matchers return a Promise so you will need to await the returned value. Let's use an example matcher to illustrate the usage of them. We are going to implement a matcher called `toBeDivisibleByExternalValue`, where the divisible number is going to be pulled from an external source.

website/versioned_docs/version-26.x/ExpectAPI.md

@@ -70,6 +70,12 @@ test('numeric ranges', () => {
 _Note_: In TypeScript, when using `@types/jest` for example, you can declare the new `toBeWithinRange` matcher in the imported module like this:
 
 ```ts
+expect.extend({
+  toBeWithinRange(received, floor, ceiling) {
+    // ...
+  },
+});
+
 interface CustomMatchers<R = unknown> {
   toBeWithinRange(floor: number, ceiling: number): R;
 }
@@ -83,6 +89,19 @@ declare global {
 }
 ```
 
+If you want to move the typings to a separate file (e.g. `types/jest/index.d.ts`), you may need to an export, e.g.:
+
+```ts
+declare global {
+  namespace jest {
+    interface Matchers<R> {
+      toBeWithinRange(a: number, b: number): R;
+    }
+  }
+}
+export {};
+```
+
 #### Async Matchers
 
 `expect.extend` also supports async matchers. Async matchers return a Promise so you will need to await the returned value. Let's use an example matcher to illustrate the usage of them. We are going to implement a matcher called `toBeDivisibleByExternalValue`, where the divisible number is going to be pulled from an external source.

website/versioned_docs/version-28.x/ExpectAPI.md

@@ -71,7 +71,15 @@ test('numeric ranges', () => {
 
 In TypeScript, when using `@types/jest` for example, you can declare the new `toBeWithinRange` matcher in the imported module like this:
 
+:::
+
 ```ts
+expect.extend({
+  toBeWithinRange(received, floor, ceiling) {
+    // ...
+  },
+});
+
 interface CustomMatchers<R = unknown> {
   toBeWithinRange(floor: number, ceiling: number): R;
 }
@@ -85,7 +93,18 @@ declare global {
 }
 ```
 
-:::
+If you want to move the typings to a separate file (e.g. `types/jest/index.d.ts`), you may need to an export, e.g.:
+
+```ts
+declare global {
+  namespace jest {
+    interface Matchers<R> {
+      toBeWithinRange(a: number, b: number): R;
+    }
+  }
+}
+export {};
+```
 
 #### Async Matchers