Returns data frame of player valuations (in Euros) from transfermarkt.com
Arguments
- country_name
the country of the league's players
- start_year
the start year of the season (2020 for the 20/21 season)
- league_url
league url from transfermarkt.com. To be used when country_name not available in main function
Value
returns a dataframe of player valuations for country/seasons