docs(db-mongodb): document Local API default limit & unlimited usage (closes #13417)

docs/local-api/overview.mdx

@@ -161,6 +161,31 @@ const result = await payload.find({
   showHiddenFields: true,
 })
 ```
+### Pagination & limits
+
+By default, Local API `find` uses the collection’s pagination settings. If no `limit` is provided, the per-page default comes from your Collection’s `pagination.defaultLimit` (defaults to **10**). See [Collection Config → pagination](../configuration/collections).
+
+To return **all** matched documents (disable pagination), either:
+
+- pass `limit: 0` (disables pagination), or
+- set `pagination: false`.
+
+```ts
+// Use the collection default (pagination.defaultLimit, defaults to 10)
+const page = await payload.find({
+  collection: 'posts',
+})
+
+// Return all matched documents (no pagination)
+const all = await payload.find({
+  collection: 'posts',
+  limit: 0,           // disables pagination
+  // or: pagination: false
+})
+
+```
+> See also: [Pagination](/docs/queries/pagination) and [Querying your Documents](/docs/queries/overview).
+
 
 ### Find by ID#collection-find-by-id