add AI safety funding

[riceissa]

http://effective-altruism.com/ea/16s/changes_in_funding_in_the_ai_safety_field/

[riceissa]

For aggregate funding and funding sources, I'm planning to do this eventually on AI Watch.

See:

• https://github.com/riceissa/project-ideas/issues/33
• https://github.com/riceissa/aiwatch/issues/1

I'm still deciding between:

• doing the individual giving on DLW and aggregating that to display on AIW
• just going ahead with aggregate funding data and doing that on AIW, and adding some of the individual stuff on DLW along the way