Add project import to the existing welcome to GitLab page

Problem

Currently, when a new user signs up, they may not be aware that we offer the ability to import existing projects from other services. The public projects can always be found when creating a project but they do not align with our goal of influencing free to paid conversion.

Solution

We should replace the existing Explore public projects with an option to Import a project this will allow new users immediately after sign up to know that we support imports.

The final solution should utilize the same module as the existing Explore public projects we should replace it with the following:

Import a project

Import from GitHub, Bitbucket, Google, Fogbugz, Gitea, Repo by URL, Manifest file, GitLab export

As seen in this mockup

ICE score

Impact	Confidence	Effort	Score
6	5	9	6.67