message: first commit - update groupmap in README
diff: @@ -75,7 +75,7 @@ The project is organized in the following way:
  * [book/](https://github.com/o1-labs/proof-systems/tree/master/book). The mina book, RFCs, and specifications.
  * [cairo/](https://github.com/o1-labs/proof-systems/tree/master/cairo). A Cairo runner written in rust.
  * [curves/](https://github.com/o1-labs/proof-systems/tree/master/curves). The elliptic curves we use (for now just the pasta curves).
  -* [groupmap/](https://github.com/o1-labs/proof-systems/tree/master/groupmap). TODO: description
  +* [groupmap/](https://github.com/o1-labs/proof-systems/tree/master/groupmap). Used to convert elliptic curve elements to field elements.
  * [kimchi/](https://github.com/o1-labs/proof-systems/tree/master/kimchi). Our proof system.
  * [ocaml/](https://github.com/o1-labs/proof-systems/tree/master/ocaml). Ocaml bindings generator tool.
  * [oracle/](https://github.com/o1-labs/proof-systems/tree/master/oracle). Implementation of the poseidon hash function.
  