Update NPM docs to remove case restriction

What does this MR do?

The changes in !53266 (merged) removed the case restriction on NPM scopes. A user owning a namespace owns it case-insensitively, meaning if I own gitlab.com/group, I also own gitlab.com/group and gitlab.com/GrOuP.

This MR removes the notes about case restrictions in the NPM scope naming convention from the docs.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

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• Label as security and @ mention @gitlab-com/gl-security/appsec
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doc/user/packages/npm_registry/index.md

@@ -208,7 +208,12 @@ Then, you can run `npm publish` either locally or by using GitLab CI/CD.
 
 When you use the [instance-level endpoint](#use-the-gitlab-endpoint-for-npm-packages), only the packages with names in the format of `@scope/package-name` are available.
 
-- The `@scope` is the root namespace of the GitLab project. To follow NPM convention, it should be lowercase, however GitLabs package registry does allow for uppercase
+- The `@scope` is the root namespace of the GitLab project. To follow npm's convention, it should be
+  lowercase. However, the GitLab package registry allows for uppercase. Before GitLab 13.10, the
+  `@scope` had to be a case-sensitive match of the GitLab project's root namespace. This was
+  problematic because the npm public registry does not allow uppercase letters. GitLab 13.10 relaxes
+  this requirement and translates uppercase in the GitLab `@scope` to lowercase for npm. For
+  example, a package `@MyScope/package-name` in GitLab becomes `@myscope/package-name` for npm.
 - The `package-name` can be whatever you want.
 
 For example, if your project is `https://gitlab.example.com/my-org/engineering-group/team-amazing/analytics`,