updates redirects

Author: korinne

public/__redirects

@@ -1527,6 +1527,7 @@
 /workers/about/tips/debugging/ /workers/observability/ 301
 /workers/testing/debugging-tools/ /workers/observability/dev-tools/ 301
 /workers/testing/local-development/ /workers/local-development/ 301
+/workers/local-development/ /workers/development-testing/ 301
 /workers/about/using-cache/ /workers/reference/how-the-cache-works/ 301
 /workers/learning/how-the-cache-works/ /workers/reference/how-the-cache-works/ 301
 /workers/api/ /api/resources/workers/subresources/scripts/methods/list/ 301