Put code snippet in code voice.

Fixes <rdar://problem/65609221>.

Author: amartini51

stdlib/public/core/SIMDVector.swift

@@ -770,7 +770,7 @@ extension SIMD where Scalar: FixedWidthInteger {
   /// Returns the sum of the scalars in the vector, computed with wrapping
   /// addition.
   ///
-  /// Equivalent to indices.reduce(into: 0) { $0 &+= self[$1] }.
+  /// Equivalent to `indices.reduce(into: 0) { $0 &+= self[$1] }`.
   @_alwaysEmitIntoClient
   public func wrappedSum() -> Scalar {
     return indices.reduce(into: 0) { $0 &+= self[$1] }