docs(power): use class references instead of strings in retryableErrorTypes examples (#172)

* Update error-handling.md

Fixed error

* Update step-operations.md

fix: use class references instead of strings in retryableErrorTypes examples

* Update error-handling.md

* Update error-handling.md

* Apply suggestion from @yaythomas

---------

Co-authored-by: thomas <18520168+yaythomas@users.noreply.github.com>

Author: TrickSumo

aws-lambda-durable-functions-power/steering/error-handling.md

@@ -121,7 +121,7 @@ const result = await context.step(
   {
     retryStrategy: createRetryStrategy({
       maxAttempts: 3,
-      retryableErrorTypes: ['NetworkError', 'TimeoutError'],
+      retryableErrorTypes: [NetworkError],
       // ValidationError won't be retried
     })
   }

aws-lambda-durable-functions-power/steering/step-operations.md

@@ -155,13 +155,21 @@ result = context.step(
 **TypeScript:**
 
 ```typescript
+class NetworkError extends Error {
+  name = 'NetworkError';
+}
+
+class TimeoutError extends Error {
+  name = 'TimeoutError';
+}
+
 const result = await context.step(
   'selective-retry',
   async () => operation(),
   {
     retryStrategy: createRetryStrategy({
       maxAttempts: 3,
-      retryableErrorTypes: ['NetworkError', 'TimeoutError']
+      retryableErrorTypes: [NetworkError, TimeoutError]
     })
   }
 );