update comment

extensions/v1alpha1/wasm.proto

@@ -243,7 +243,8 @@ message WasmPlugin {
   // namespace of the `WasmPlugins`. Defaults to `0`.
   google.protobuf.Int64Value priority = 10;
 
-  // Configuration for finding or starting VM.
+  // Configuration for a Wasm VM.
+  // more details can be found [here](https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/wasm/v3/wasm.proto#extensions-wasm-v3-vmconfig).
   VmConfig vm_config = 11;
 }
 
@@ -286,13 +287,10 @@ enum PullPolicy {
 }
 
 // Configuration for a Wasm VM.
+// more details can be found [here](https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/wasm/v3/wasm.proto#extensions-wasm-v3-vmconfig).
 message VmConfig {
-  // Specifies environment variables to be injected to this VM which will be available through
-  // WASI's ``environ_get`` and ``environ_get_sizes`` system calls. Note that these functions are mostly implicitly
-  // called in your language's standard library, so you do not need to call them directly and you can access to env
-  // vars just like when you do on native platforms.
-  // Warning: Envoy rejects the configuration if there's conflict of key space.
-  EnvironmentVariables environment_variables = 4;
+  // Specifies environment variables to be injected to this VM.
+  EnvironmentVariables environment_variables = 1;
 }
 
 message EnvironmentVariables {