[META] Rework of the welcome page for new empty project

A few issues have been opened recently that are about reworking the look and content of the welcoming page for a new empty (without README) project. These issues are listed below. This meta-issue can be used to coordinate the efforts between the different issues, and for the community to propose other changes that they may find relevant.

• New project welcome page does not propose the possibility to run git config for local project
• Welcome page for new project does not propose HTTPS for git
• Adding 'Copy to clipboard' buttons into the Command line instructions after creating a blank new project (see MR)

CC @stingrayza @mathild3riou @NicolasNickPro @slejeune