API Endpoint to add a member to an organisation

[culmat]

completing API Endpoints for organization members #645

[lafriks]

Thanks for PR but there is no real need in Gitea for this method as we have already removed from interface as adding user to org members without adding to team does not give anything (including rights to see any private repos etc) as Gitea has a bit different rights model

[culmat]

I see now.
PUT /teams/{id}/members/{username} Add a team member
also adds to the org. I was mislead by the error message "Must be an organization member". It occurred when listing the teams on /orgs/{orgName}/teams.
Closing this.