modify read me

Author: luigi

codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/README.md

@@ -29,6 +29,7 @@ While Ktor is the default backend, the architecture is framework-agnostic, allow
 - `ServiceStubGenerator.kt` – abstract service stub generator file.
 - `ServiceTypes.kt` – file that includes service component symbols.
 - `utils.kt` – utilities file.
+- `BuildScriptGenerator.kt` – build scripts generator file.
 
 ### Testing
 

codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/docs/GettingStarted.md

@@ -136,6 +136,22 @@ Run:
   gradle build
 ```
 
+⚠️ Running gradle build will delete the previous build output before creating a new one.
+
+If you want to prevent accidentally losing previous build, use the provided scripts instead:
+
+Linux / macOS:
+```bash
+  chmod +x build.sh
+  ./build.sh
+```
+
+Windows:
+```bash
+  icacls build.bat /grant %USERNAME%:RX
+  .\build.bat
+```
+
 If you want to clean previously generated code:
 ```bash
   gradle clean