🤖 Merge PR DefinitelyTyped#74381 Update README with guidance on updating the types by @Tantalon

Author: Tantalon

types/aws-synthetics-puppeteer/README.md

@@ -3,7 +3,7 @@ Types for writing AWS Synthetic Canaries using the syn-nodejs-puppeteer runtime.
 ### Structure
 
 The syn-nodejs-puppeteer runtime has an unusual structure - files are in node_modules with no package!
-````
+```
 nodejs/node_modules/Synthetics.js
 nodejs/node_modules/SyntheticsLogger.js
 nodejs/node_modules/SyntheticsScreenshot.js
@@ -13,3 +13,10 @@ Because of this, every type definition file declares it's own module, similar to
 
 If you choose to define "types" in tsconfig, it must include this package for it to work.
 
+### Contributions
+
+Please ensure that changes are aligned with the runtime.
+You can download the runtime with this command (you need to be logged into AWS, any account will do):
+```
+aws lambda get-layer-version-by-arn --arn arn:aws:lambda:us-east-1:378653112637:layer:Synthetics:73 --query Content.Location --output text
+```