Add nsf badge (#1830)
Add nsf badge (#1830)

* add nsf badge

* Update README.rst

* Update README.rst

Co-authored-by: Daniel S. Katz <636bc94bf4963788d6c9e373695568722eb91365@ieee.org>
Co-authored-by: Yadu Nand Babuji <d4d52b73e992a1e02c7e71afc690d71169073308@gmail.com>
Parsl/parsl,Parsl/parsl,Parsl/parsl,Parsl/parsl