Returns the transfermarkt URLs for all staff of selected roles for a given team
tm_team_staff_urls(team_urls, staff_role)the staff member's team URL (can be from tm_league_team_urls())
role of the staff member URLs required for with options including:
"Manager", "Assistant Manager", "Goalkeeping Coach", "Fitness Coach", "Conditioning Coach"
returns a character vector of all transfermarkt staff URLs for a selected team(s)