Update links to MR docs

Update links in various pages to updated locations

doc/administration/incoming_email.md

@@ -7,7 +7,7 @@ GitLab has several features based on receiving incoming emails:
 - [New issue by email](../user/project/issues/managing_issues.md#new-issue-via-email):
   allow GitLab users to create a new issue by sending an email to a
   user-specific email address.
-- [New merge request by email](../user/project/merge_requests/index.md#create-new-merge-requests-by-email):
+- [New merge request by email](../user/project/merge_requests/creating_merge_requests.md#create-new-merge-requests-by-email):
   allow GitLab users to create a new merge request by sending an email to a
   user-specific email address.
 - [Service Desk](../user/project/service_desk.md): provide e-mail support to
@@ -79,7 +79,7 @@ email address in order to sign up.
 If you also host a public-facing GitLab instance at `hooli.com` and set your
 incoming email domain to `hooli.com`, an attacker could abuse the "Create new
 issue by email" or
-"[Create new merge request by email](../user/project/merge_requests/index.md#create-new-merge-requests-by-email)"
+"[Create new merge request by email](../user/project/merge_requests/creating_merge_requests.md#create-new-merge-requests-by-email)"
 features by using a project's unique address as the email when signing up for
 Slack, which would send a confirmation email, which would create a new issue or
 merge request on the project owned by the attacker, allowing them to click the

doc/administration/index.md

@@ -119,7 +119,7 @@ Learn how to install, configure, update, and maintain your GitLab instance.
 - [Auditor users](auditor_users.md): Users with read-only access to all projects, groups, and other resources on the GitLab instance. **(PREMIUM ONLY)**
 - [Incoming email](incoming_email.md): Configure incoming emails to allow
   users to [reply by email](reply_by_email.md), create [issues by email](../user/project/issues/managing_issues.md#new-issue-via-email) and
-  [merge requests by email](../user/project/merge_requests/index.md#create-new-merge-requests-by-email), and to enable [Service Desk](../user/project/service_desk.md).
+  [merge requests by email](../user/project/merge_requests/creating_merge_requests.md#create-new-merge-requests-by-email), and to enable [Service Desk](../user/project/service_desk.md).
   - [Postfix for incoming email](reply_by_email_postfix_setup.md): Set up a
   basic Postfix mail server with IMAP authentication on Ubuntu for incoming
   emails.

doc/user/admin_area/diff_limits.md

@@ -6,7 +6,7 @@ type: reference
 
 You can set a maximum size for display of diff files (patches).
 
-For details about diff files, [View changes between files](../project/merge_requests/index.md#view-changes-between-file-versions).
+For details about diff files, [View changes between files](../project/merge_requests/creating_merge_requests.md#view-changes-between-file-versions).
 
 ## Maximum diff patch size
 

doc/user/group/index.md

@@ -75,7 +75,7 @@ By doing so:
 ## Issues and merge requests within a group
 
 Issues and merge requests are part of projects. For a given group, you can view all of the
-[issues](../project/issues/index.md#issues-list) and [merge requests](../project/merge_requests/index.md#view-group-merge-requests) across all projects in that group,
+[issues](../project/issues/index.md#issues-list) and [merge requests](../project/merge_requests/reviewing_and_managing_merge_requests.md#view-group-merge-requests) across all projects in that group,
 together in a single list view.
 
 ### Bulk editing issues and merge requests