SDK: Prep SDK & types packages for release

With the upcoming release of the new extension, we should also publish our @heliax/namada-sdk and @namada/types packages to npmjs.com

Finalize API for SDK
- Build, Sign, & Broadcast APIs - DONE
- 1033
  - build_ functions now return a deserialized object, which can be inspected & destructured
  - namada.sign() now has a decent API:
```
tx: TxProps | TxProps[],
signer: string,
checksums?: Record<string, string>
```
  - sdk.rpc.broadcastTx() now has simplified props:
```
async broadcastTx(
signedTxBytes: Uint8Array,
args: WrapperTxProps
): Promise<TxResponseProps>
```
- Any changes to other rpc APIs? With the indexer package, these are not likely to be used regularly, only in cases where a client needs to communicate directly with a node (i.e., broadcastTx()) - What we have is fine for direct integration with the SDK RPC, and is in the documentation. Users will likely primarily use the Indexer package for these tasks, and any updates to sdk.rpc won't introduce breaking changes to the extension or Namadillo, these are merely a TypeScript front-end lib for our @namada/shared package
- If there are any useful re-exports we can add (such as the Tx props types), add them now - DONE
- Finalize docs - DONE
@namada/types
- Add yarn build:docs - https://github.com/anoma/namada-interface/pull/918
- Commit docs and update README

anoma / namada-interface