Update README.md

Author: ianamason

README.md

@@ -257,7 +257,7 @@ LTO Support
 In some situations it is desirable to pass certain flags to clang in the step that
 produces the bitcode. This can be fulfilled by setting the 
 `LLVM_BITCODE_GENERATION_FLAGS` environment variable to the desired 
-flags, for example "-flto -fwhole-program-vtables".
+flags, for example `"-flto -fwhole-program-vtables"`.
 
 Debugging
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