Add ambassadors to website

[samumantha]

Currently wish to be on website:

• Raphaela Heil (Uppsala, Sweden), raphaela.m.heil@gmail.com (without affiliation for now)
• Ding He, dinghe@biosustain.dtu.dk (Technical Univeristy of Denmark, Denmark)
• Yonglei Wang, yonglei@nsc.liu.se