Add auth sdk page (#110)

(cherry picked from commit 418a618)

Author: leighmcculloch

docs/SDKs/rust-auth.mdx

@@ -0,0 +1,40 @@
+---
+sidebar_position: 2
+title: Soroban Rust Auth SDK
+---
+
+The `soroban-auth` Rust crate contains the Soroban Rust Auth SDK. It provides
+utilities for verifying signatures on invocations of smart contracts.  It is
+intended for use alongside the [`soroban-sdk`].
+
+[`soroban-sdk`]: rust
+
+:::caution
+The `soroban-auth` crate is in early development. Report issues
+[here](https://github.com/stellar/rs-soroban-sdk/issues/new/choose).
+:::
+
+## SDK Documentation
+
+Auth documentation is available at:
+https://docs.rs/soroban-auth
+
+## Subscribe to Releases
+
+Subscribe to releases on the GitHub repository:
+https://github.com/stellar/rs-soroban-sdk
+
+## Add `soroban-auth` as a Dependency
+
+Add the following sections to the `Cargo.toml` to import `soroban-auth`.
+
+```toml
+[features]
+testutils = ["soroban-auth/testutils"]
+
+[dependencies]
+soroban-auth = "0.0.4"
+
+[dev_dependencies]
+soroban-auth = { version = "0.0.4", features = ["soroban-auth/testutils"] }
+```

docs/examples/authorization.mdx

@@ -36,6 +36,21 @@ test test::test ... ok
 test test::bad_data - should panic ... ok
 ```
 
+## Dependencies
+
+The authorization example uses the Soroban auth SDK, and has the following
+Soroban dependencies in its Cargo.toml file.
+
+```toml title="authorization/src/Cargo.toml
+[dependencies]
+soroban-sdk = "0.0.4"
+soroban-auth = "0.0.4"
+
+[dev_dependencies]
+soroban-sdk = { version = "0.0.4", features = ["testutils"] }
+soroban-auth = { version = "0.0.4", features = ["testutils"] }
+```
+
 ## Code
 
 ```rust title="authorization/src/lib.rs"