message: Add MIGRATING entry for custom querier types
diff: @@ -35,6 +35,53 @@ major releases of `cosmwasm`. Note that you can also view the
  annotations. See the [0.13 -> 0.14 entry](#013---014) where `#[entry_point]`
  was introduced.
  +- If your chain provides a custom queries, add the custom query type as a
  + generic argument to `cosmwasm_std::Deps`, `DepsMut`, `OwnedDeps` and
  + `QuerierWrapper`. Otherwise it defaults to `Empty`. E.g.
  +
  + ```diff
  + #[entry_point]
  + pub fn instantiate(
  + - deps: DepsMut,
  + + deps: DepsMut<CyberQueryWrapper>,
  + _env: Env,
  + info: MessageInfo,
  + msg: InstantiateMsg,
  + @@ -38,112 +35,95 @@ pub fn instantiate(
  + }
  + ```
  +
  + ```diff
  + #[entry_point]
  + -pub fn query(deps: Deps, _env: Env, msg: QueryMsg) -> StdResult<Binary> {
  + +pub fn query(deps: Deps<CyberQueryWrapper>, _env: Env, msg: QueryMsg) -> StdResult<Binary> {
  + match msg {
  + ```
  +
  + ```diff
  + pub struct CyberQuerier<'a> {
  + - querier: &'a QuerierWrapper<'a>,
  + + querier: &'a QuerierWrapper<'a, CyberQueryWrapper>,
  + }
  +
  + impl<'a> CyberQuerier<'a> {
  + - pub fn new(querier: &'a QuerierWrapper) -> Self {
  + + pub fn new(querier: &'a QuerierWrapper<'a, CyberQueryWrapper>) -> Self {
  + CyberQuerier { querier }
  + }
  + }
  + ```
  +
  + Replace `QuerierWrapper::custom_query` with `QuerierWrapper::query` which is
  + now fully typed:
  +
  + ```diff
  + -let res: CyberlinksAmountResponse = self.querier.custom_query(&request.into())?;
  + +let res: CyberlinksAmountResponse = self.querier.query(&request.into())?;
  + ```
  +
  + See https://github.com/cybercongress/cw-cyber/pull/2 for a complete example.
  +
  ### Integration tests
  - Add new `transaction` field to `Env` when creating a custom mock env:
  