Adding a tag Free / Freemium

[sebastienserre]

Hello,

This ticket follow a discussion hold in the French WP Slack about completely free and freemium plugins.

Several folks think we should know before installing a plugin if it's a free plugin or a freemium plugin.

For some people it's a search criteria to not have paying features in the plugin they will install.

We think about a tag in the header which add an icon in the Plugin directory and in the WP Backend.

What do you think about this idea?

[jeherve]

Related: #1358