Update NDC Spec to v0.2.0-rc.2 (#40)

This is just a types update, no real changes.

Also includes the changes from #39 because the build got stuck on that
PR.

---------

Co-authored-by: Alexander Salas Bastidas <[email protected]>

Author: daniel-chambers

Diff for: Cargo.lock

@@ -9,8 +9,8 @@ members = ["crates/*"]
 
 [workspace.dependencies]
 ndc-sdk-core = { path = "../sdk-core" }
-ndc-models = { git = "http://github.com/hasura/ndc-spec.git", tag = "v0.2.0-rc.1" }
-ndc-test = { git = "http://github.com/hasura/ndc-spec.git", tag = "v0.2.0-rc.1" }
+ndc-models = { git = "http://github.com/hasura/ndc-spec.git", tag = "v0.2.0-rc.2" }
+ndc-test = { git = "http://github.com/hasura/ndc-spec.git", tag = "v0.2.0-rc.2" }
 
 anyhow = "1"
 async-trait = "0.1"

Diff for: Cargo.toml

@@ -22,7 +22,7 @@ cargo build
 
 ```sh
 mkdir empty
-cargo run --bin ndc_hub_example -- --configuration ./empty
+cargo run --bin ndc_hub_example serve --configuration ./empty
 ```
 
 Inspect the resulting (empty) schema: