message: Make contract update instructions a single command
diff: @@ -21,8 +21,8 @@ To rebuild the test contract, go to the repo root and do
  docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="$(basename "$(pwd)")_cache",target=/code/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  - confio/cosmwasm-opt:0.7.3 ./contracts/hackatom
  -cp contracts/hackatom/contract.wasm packages/vm/testdata/contract_0.8.wasm
  + confio/cosmwasm-opt:0.7.3 ./contracts/hackatom \
  + && cp contracts/hackatom/contract.wasm packages/vm/testdata/contract_0.8.wasm
  ```
  You can do the same for `reflect` and `queue` when there are breaking changes.
  