Update wording around GitLab.com upload limits

As mentioned in https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/9997

doc/user/gitlab_com/index.md

@@ -89,7 +89,7 @@ or over the size limit, you can [reduce your repository size with Git](../projec
 | Repository size including LFS | 10G         | Unlimited     |
 
 NOTE: **Note:**
-A single `git push` is limited to 5GB. LFS is not affected by this limit.
+`git push` and GitLab project imports are limited to 5GB per request. Git LFS and imports other than a file upload are not affected by this limit.
 
 ## IP range