improved tooltip and fix small issue
improved tooltip and fix small issue

Hacker0x01/radar-chart-d3,Hacker0x01/radar-chart-d3,martijnrusschen/radar-chart-d3,nagyistoce/radar-chart-d3,alangrafu/radar-chart-d3,Squarespace/radar-chart-d3,martijnrusschen/radar-chart-d3,nagyistoce/radar-chart-d3,alangrafu/radar-chart-d3,Squarespace/radar-chart-d3