docs: update GraphQL docs for child fields (#28976)

This reverts commit 8687e2c

Author: vladar

docs/docs/reference/graphql-data-layer/schema-customization.md

@@ -224,7 +224,7 @@ The types passed in are used to determine child relations of the node.
 
 #### Defining child relations
 
-The `@childOf` extension can be used to explicitly define what node types or media types a node is a child of and immediately add `child[MyType]` or `children[MyType]` as a field on the parent.
+The `@childOf` extension can be used to explicitly define what node types or media types a node is a child of and immediately add `child[MyType]` and `children[MyType]` fields on the parent.
 
 The `types` argument takes an array of strings and determines what node types the node is a child of:
 
@@ -255,20 +255,6 @@ type Mdx implements Node
 }
 ```
 
-If `many: true` is set, then instead of creating a single child field on the parent, it will create multiple:
-
-```graphql
-# Adds `childMdx1` with type `Mdx1` to `File`.
-type Mdx1 implements Node @childOf(types: ["File"]) {
-  id: ID!
-}
-
-# Adds `childrenMdx2` with type `[Mdx2]` as a field of `File`.
-type Mdx2 implements Node @childOf(types: ["File"], many: true) {
-  id: ID!
-}
-```
-
 #### Nested types
 
 So far, the example project has only been dealing with scalar values (`String` and `Date`;

docs/docs/schema-generation.md

@@ -38,7 +38,7 @@ This allows adding GraphQL Fields to any node type. This operates on GraphQL typ
 
 ## 4. Parent / children relationships
 
-Nodes can be connected into _child-parent_ relationships either by using [`createParentChildLink`](/docs/reference/config-files/actions/#createParentChildLink) or by adding the `parent` field to raw node data. Child types can always access parent with the `parent` field in GraphQL. Parent types also get `children` fields as well as "convenience child fields" `child[TypeName]` or `children[TypeName]`.
+Nodes can be connected into _child-parent_ relationships either by using [`createParentChildLink`](/docs/reference/config-files/actions/#createParentChildLink) or by adding the `parent` field to raw node data. Child types can always access parent with the `parent` field in GraphQL. Parent types also get `children` fields as well as "convenience child fields" `child[TypeName]` and `children[TypeName]`.
 
 Children types are either inferred from data or created using `@childOf` directive, either by parent type name or by `mimeType` (only for File parent types).