Write documentation for manual vulnerability

doc/user/application_security/vulnerability_report/index.md

@@ -52,6 +52,7 @@ From the Vulnerability Report you can:
 - [View an issue raised for a vulnerability](#view-issues-raised-for-a-vulnerability).
 - [Change the status of vulnerabilities](#change-status-of-vulnerabilities).
 - [Export details of vulnerabilities](#export-vulnerability-details).
+- [Manually add a vulnerability finding](#manually-add-a-vulnerability-finding).
 
 ## Vulnerability Report filters
 
@@ -219,6 +220,25 @@ You can dismiss a vulnerability for the entire project:
 
 To undo this action, select a different status from the same menu.
 
+## Manually add a vulnerability finding
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/301003) in GitLab 14.9. Disabled by default.
+
+FLAG:
+This feature is not enabled by default. To make it available, ask an administrator to 
+[enable the feature flag](../../feature_flags.md) named `new_vulnerability_form`. 
+On GitLab.com, this feature is not yet available.
+
+To add a new vulnerability finding from your project level Vulnerability Report page:
+
+1. On the top bar, select **Menu > Projects** and find your project.
+1. On the left sidebar, select **Security & Compliance > Vulnerability Report**.
+1. Click on **Submit Vulnerability**.
+1. Complete the fields and submit the form.
+
+You will be brought to the newly created vulnerability's detail page. Manually created records appear in the 
+Group, Project, and Security Center Vulnerability Reports. To filter them, use the Generic Tool filter.
+
 ## Operational vulnerabilities
 
 > [Introduced](https://gitlab.com/groups/gitlab-org/-/epics/6345) in GitLab 14.6.