message: bazel update readme
diff: @@ -2,6 +2,9 @@ This repository contains various zk-SNARK protocol implementations for recursive
  Build all targets: `$ bazel build //...` (note: three dots)
  +Note that the Zexe submodule is encoded as a Bazel workspace, so you
  +cannot build it directly by e.g. `bazel build //zexe/algebra`. Instead
  +you must use the Zexe workspace name: `baze build @zexe//algebra`.
  ## Bazel maintenance
  