message: Format migrating docs
diff: @@ -51,8 +51,9 @@ Contract Code:
  - You can also replace `to_vec(...)` with `to_binary(...)`
  - No `.context(...)` is required after `from_slice` and `to_vec`, they return
  proper `cosmwasm_std::Error` variants on errors.
  -- If you used `env.contract.balance`, you must now use the querier.
  - The following code block should work:
  +- If you used `env.contract.balance`, you must now use the querier. The
  + following code block should work:
  +
  ```rust
  // before (in env)
  let foo = env.contract.balance;
  @@ -78,9 +79,10 @@ Both:
  `Coin::new` and returns one `Coin`.
  - Remove the 4th argument (contract balance) from all calls to `mock_env`, this
  is no longer stored in the environment.
  -- `mock_dependencies` and `mock_instance` take a 2nd argument to set the contract
  - balance (visible for the querier). If you need to set more balances, use
  - `mock_XX_with_balances`. The follow code block explains:
  +- `mock_dependencies` and `mock_instance` take a 2nd argument to set the
  + contract balance (visible for the querier). If you need to set more balances,
  + use `mock_XX_with_balances`. The follow code block explains:
  +
  ```rust
  // before: balance as last arg in mock_env
  let mut deps = mock_dependencies(20);
  