Update sycl/doc/developer/ContributeToDPCPP.md

Author: bader

sycl/doc/developer/ContributeToDPCPP.md

@@ -64,6 +64,7 @@ end-to-end or SYCL-CTS tests.
 
 - All identifiers used in `llvm/sycl` headers and source files must contain at
   least one lowercase letter due to avoid conflicts with user-defined macros.
+
 - Try to follow descriptive naming convention for variables, functions as
   much as possible. Please refer to
   [LLVM naming convention](https://llvm.org/docs/CodingStandards.html#name-types-functions-variables-and-enumerators-properly)