Internal change

PiperOrigin-RevId: 838752482

Author: protobuf-github-bot

content/best-practices/1-1-1.md

@@ -13,7 +13,7 @@ single `proto_library` build rule. This approach promotes small, modular proto
 definitions. Key benefits include simplified refactoring, potentially improved
 build times, and smaller binary sizes due to minimized transitive dependencies.
 
---------------------------------------------------------------------------------
+## Rationale
 
 The 1-1-1 best practice is to keep every proto_library and .proto file as small
 as is reasonable, with the ideal being: