Merge pull request #850 from z63d/fix/doc-comment

fix: Corrected description of containerd_address from GRPC to ttrpc

crates/containerd-shim-wasm/src/sandbox/instance.rs

@@ -22,7 +22,7 @@ pub struct InstanceConfig {
     bundle: PathBuf,
     /// Namespace for containerd
     namespace: String,
-    // /// GRPC address back to main containerd
+    /// ttrpc address back to main containerd
     containerd_address: String,
 }