docs: fix the signature of CacheHandler#revalidateTag (vercel#70286)

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docs: fix the signature of CacheHandler#revalidateTag

My tests shows that the `tags` could be an array.

I have traced it back to the code:


https://github.com/vercel/next.js/blob/af9b229074e39617bdd32d390fdc8f6a36d7bcde/packages/next/src/server/lib/incremental-cache/index.ts#L246-L248

---------

Co-authored-by: malewis5 <matthew.a.lewis7@gmail.com>
Co-authored-by: JJ Kasper <jj@jjsweb.site>

docs/02-app/01-building-your-application/10-deploying/index.mdx

@@ -175,11 +175,13 @@ module.exports = class CacheHandler {
     })
   }
 
-  async revalidateTag(tag) {
+  async revalidateTag(tags) {
+    // tags is either a string or an array of strings
+    tags = [tags].flat()
     // Iterate over all entries in the cache
     for (let [key, value] of cache) {
       // If the value's tags include the specified tag, delete this entry
-      if (value.tags.includes(tag)) {
+      if (value.tags.some((tag) => tags.include(tag))) {
         cache.delete(key)
       }
     }

docs/02-app/02-api-reference/05-next-config-js/incrementalCacheHandlerPath.mdx

@@ -43,9 +43,9 @@ Returns `Promise<void>`.
 
 ### `revalidateTag()`
 
-| Parameter | Type     | Description                  |
-| --------- | -------- | ---------------------------- |
-| `tag`     | `string` | The cache tag to revalidate. |
+| Parameter | Type                   | Description                   |
+| --------- | ---------------------- | ----------------------------- |
+| `tag`     | `string` or `string[]` | The cache tags to revalidate. |
 
 Returns `Promise<void>`. Learn more about [revalidating data](/docs/app/building-your-application/data-fetching/incremental-static-regeneration) or the [`revalidateTag()`](/docs/app/api-reference/functions/revalidateTag) function.