Set up audit report GraphQL example

doc/api/graphql/audit_report.md

+# Set up an Audit Report with GraphQL
+
+This page describes how you can use the GraphiQL explorer to set up an audit report
+for a specific subset of users.
+
+You can run the same query directly via a HTTP endpoint, using `cURL`. For more information, see our
+guidance on getting started from the [command line](getting_started.md#command-line).
+
+The [example users query](#set-up-the-graphiql-explorer) looks for a subset of users in
+a GitLab instance either by username or
+[global ID](../../development/api_graphql_styleguide.md#exposing-global-ids). The query
+includes:
+
+- [`pageInfo`](#pageinfo)
+- [`nodes`](#nodes)
+
+## pageInfo
+
+This contains the data needed to implement pagination. GitLab uses cursor-based
+[pagination](getting_started.md#pagination). For more information, see
+[Pagination](https://graphql.org/learn/pagination/) in the GraphQL documentation.
+
+## nodes
+
+In a GraphQL query, `nodes` is used to represent a collection of [`nodes` on a graph](https://en.wikipedia.org/wiki/Vertex_(graph_theory)).
+In this case, the collection of nodes is a collection of `User` objects. For each one,
+we output:
+
+- Their user's `id`.
+- The `membership` fragment, which represents a Project or Group membership belonging
+  to that user. Outputting a fragment is denoted with the `...memberships` notation.
+
+The GitLab GraphQL API is extensive and a large amount of data for a wide variety of entities can be output.
+See the official [reference documentation](reference/index.md) for the most up-to-date information.
+
+## Set up the GraphiQL explorer
+
+This procedure presents a substantive example that you can copy and paste into GraphiQL
+explorer. GraphiQL explorer is available for:
+
+- GitLab.com users at [https://gitlab.com/-/graphql-explorer](https://gitlab.com/-/graphql-explorer).
+- Self-managed users at `https://gitlab.example.com/-/graphql-explorer`.
+
+1. Copy the following code excerpt:
+
+   ```graphql
+   {
+     users(usernames: ["user1", "user2", "user3"]) {
+       pageInfo {
+         endCursor
+         startCursor
+         hasNextPage
+       }
+       nodes {
+         id
+         ...memberships
+       }
+     }
+   }
+
+   fragment membership on MemberInterface {
+     createdAt
+     updatedAt
+     accessLevel {
+       integerValue
+       stringValue
+     }
+     createdBy {
+       id
+     }
+   }
+
+   fragment memberships on User {
+     groupMemberships {
+       nodes {
+         ...membership
+         group {
+           id
+           name
+         }
+       }
+     }
+
+     projectMemberships {
+       nodes {
+         ...membership
+         project {
+           id
+           name
+         }
+       }
+     }
+   }
+   ```
+
+1. Open the [GraphiQL explorer tool](https://gitlab.com/-/graphql-explorer).
+1. Paste the `query` listed above into the left window of your GraphiQL explorer tool.
+1. Click Play to get the result shown here:
+
+![GraphiQL explorer search for boards](img/user_query_example_v13_2.png)
+
+NOTE: **Note:**
+[The GraphQL API returns a GlobalID, rather than a standard ID.](getting_started.md#queries-and-mutations) It also expects a GlobalID as an input rather than
+a single integer.
+
+This GraphQL query returns the groups and projects that the user has been *explicitly* made a member of.
+Since the GraphiQL explorer uses the session token to authorize access to resources,
+the output is limited to the projects and groups accessible to the currently signed-in user.
+
+If you've signed in as an instance administrator, you would have access to all records, regardless of ownership.
+
+For more information on:
+
+- GraphQL specific entities, such as Fragments and Interfaces, see the official
+  [GraphQL documentation](https://graphql.org/learn/).
+- Individual attributes, see the [GraphQL API Resources](reference/index.md).