Update documentation for invite modal feature flag

doc/user/group/index.md

@@ -262,6 +262,9 @@ To view the activity feed in Atom format, select the
 
 > [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/18328) in GitLab 12.7.
 
+NOTE:
+In GitLab 13.11, you can [replace this form with a modal window](#share-a-group-modal-window).
+
 Similar to how you [share a project with a group](../project/members/share_project_with_groups.md),
 you can share a group with another group. Members get direct access
 to the shared group. This is not valid for inherited members.
@@ -278,6 +281,27 @@ To share a given group, for example, `Frontend` with another group, for example,
 
 All the members of the `Engineering` group are added to the `Frontend` group.
 
+### Share a group modal window
+
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/247208) in GitLab 13.11.
+> - [Deployed behind a feature flag](../feature_flags.md), disabled by default.
+> - Enabled on GitLab.com.
+> - Recommended for production use.
+> - Replaces the existing form with buttons to open a modal window.
+> - To use in GitLab self-managed instances, ask a GitLab administrator to [enable it](../project/members/index.md#enable-or-disable-modal-window). **(FREE SELF)**
+
+WARNING:
+This feature might not be available to you. Check the **version history** note above for details.
+
+In GitLab 13.11, you can optionally replace the sharing form with a modal window.
+To share a group after enabling this feature:
+
+1. Go to your group's page.
+1. In the left sidebar, go to **Members**, and then select **Invite a group**.
+1. Select a group, and select a **Max access level**.
+1. (Optional) Select an **Access expiration date**.
+1. Select **Invite**.
+
 ## Manage group memberships via LDAP **(PREMIUM SELF)**
 
 Group syncing allows LDAP groups to be mapped to GitLab groups. This provides more control over per-group user management. To configure group syncing, edit the `group_base` **DN** (`'OU=Global Groups,OU=GitLab INT,DC=GitLab,DC=org'`). This **OU** contains all groups that will be associated with GitLab groups.

doc/user/project/members/index.md

@@ -109,6 +109,9 @@ had on the project you imported from are retained.
 
 ## Invite people using their e-mail address
 
+NOTE:
+In GitLab 13.11, you can [replace this form with a modal window](#add-a-member-modal-window).
+
 If a user you want to give access to doesn't have an account on your GitLab
 instance, you can invite them just by typing their e-mail address in the
 user search field.
@@ -135,6 +138,46 @@ GitLab account using the same e-mail address the invitation was sent to.
 NOTE:
 Unaccepted invites are automatically deleted after 90 days.
 
+### Add a member modal window
+
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/247208) in GitLab 13.11.
+> - [Deployed behind a feature flag](../../feature_flags.md), disabled by default.
+> - Enabled on GitLab.com.
+> - Recommended for production use.
+> - Replaces the existing form with buttons to open a modal window.
+> - To use in GitLab self-managed instances, ask a GitLab administrator to [enable it](#enable-or-disable-modal-window). **(FREE SELF)**
+
+WARNING:
+This feature might not be available to you. Check the **version history** note above for details.
+
+In GitLab 13.11, you can optionally replace the form to add a member with a modal window.
+To add a member after enabling this feature:
+
+1. Go to your project's page.
+1. In the left sidebar, go to **Members**, and then select **Invite members**.
+1. Enter an email address, and select a role permission for this user.
+1. (Optional) Select an **Access expiration date**.
+1. Select **Invite**.
+
+### Enable or disable modal window **(FREE SELF)**
+
+The modal window for adding a member is under development and is ready for production use. It is
+deployed behind a feature flag that is **disabled by default**.
+[GitLab administrators with access to the GitLab Rails console](../../../administration/feature_flags.md)
+can enable it.
+
+To enable it:
+
+```ruby
+Feature.enable(:invite_members_group_modal)
+```
+
+To disable it:
+
+```ruby
+Feature.disable(:invite_members_group_modal)
+```
+
 ## Project membership and requesting access
 
 Project owners can :

doc/user/project/members/share_project_with_groups.md

@@ -17,6 +17,9 @@ members.
 
 ## Sharing a project with a group of users
 
+NOTE:
+In GitLab 13.11, you can [replace this form with a modal window](#share-a-project-modal-window).
+
 The primary mechanism to give a group of users, say 'Engineering', access to a project,
 say 'Project Acme', in GitLab is to make the 'Engineering' group the owner of 'Project
 Acme'. But what if 'Project Acme' already belongs to another group, say 'Open Source'?
@@ -48,6 +51,46 @@ Note that you can only share a project with:
 
 Administrators are able to share projects with any group in the system.
 
+### Share a project modal window
+
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/247208) in GitLab 13.11.
+> - [Deployed behind a feature flag](../../feature_flags.md), disabled by default.
+> - Enabled on GitLab.com.
+> - Recommended for production use.
+> - Replaces the existing form with buttons to open a modal window.
+> - To use in GitLab self-managed instances, ask a GitLab administrator to [enable it](#enable-or-disable-modal-window). **(FREE SELF)**
+
+WARNING:
+This feature might not be available to you. Check the **version history** note above for details.
+
+In GitLab 13.11, you can optionally replace the sharing form with a modal window.
+To share a project after enabling this feature:
+
+1. Go to your project's page.
+1. In the left sidebar, go to **Members**, and then select **Invite a group**.
+1. Select a group, and select a **Max access level**.
+1. (Optional) Select an **Access expiration date**.
+1. Select **Invite**.
+
+### Enable or disable modal window **(FREE SELF)**
+
+The modal window for sharing a project is under development and is ready for production use. It is
+deployed behind a feature flag that is **disabled by default**.
+[GitLab administrators with access to the GitLab Rails console](../../../administration/feature_flags.md)
+can enable it.
+
+To enable it:
+
+```ruby
+Feature.enable(:invite_members_group_modal)
+```
+
+To disable it:
+
+```ruby
+Feature.disable(:invite_members_group_modal)
+```
+
 ## Maximum access level
 
 In the example above, the maximum access level of 'Developer' for members from 'Engineering' means that users with higher access levels in 'Engineering' ('Maintainer' or 'Owner') only have 'Developer' access to 'Project Acme'.