document areas of the codebase with prototype pollution

Author: aduh95

doc/contributing/primordials.md

@@ -9,6 +9,7 @@ important than reliability against prototype pollution:
 
 * `node:http`
 * `node:http2`
+* `node:tls`
 
 Usage of primordials should be preferred for new code in other areas, but
 replacing current code with primordials should be