smithy-rs

* Implement RFC 23, with the exception of PluginBuilder

* Update documentation.

* Elide implementation details in `Upgradable`.

* Update wording in docs to avoid personal pronouns.

* Update `Upgradable`'s documentation.

* Template the service builder name.

* Template MissingOperationsError directly.

* Code-generate an array directly.

* Update design/src/server/anatomy.md

Co-authored-by: david-perez <d@vidp.dev>

* Use `rust` where we do not need templating.

* Remove unused variable.

* Add `expect` message to point users at our issue board in case a panic slips through.

* Typo.

* Update `expect` error message.

* Refactor the `for` loop in ``requestSpecMap` into an `associateWith` call.

* Fix new pokemon bin example.

* Fix new pokemon bin example.

* Fix unresolved symbolProvider.

* Assign the `expect` error message to a variable.

* Omit additional generic parameters in Upgradable when it's first introduced.

Co-authored-by: david-perez <d@vidp.dev>