test(rust-doc-in-enum): Add reproducing example for issue #5662

[1] #5662

Author: malikolivier

Diff for: tests/target/rust-doc-in-enum/horizontal-no-doc.rs

@@ -0,0 +1,6 @@
+enum MyType {
+    A { field1: bool, field2: bool },
+    B { field1: bool, field2: bool },
+    C { field1: bool, field2: bool },
+    D { field1: bool, field2: bool },
+}

Diff for: tests/target/rust-doc-in-enum/horizontal-with-doc.rs

@@ -0,0 +1,7 @@
+enum MyType {
+    A { field1: bool, field2: bool },
+    B { field1: bool, field2: bool },
+    /// OMG a comment
+    C { field1: bool, field2: bool },
+    D { field1: bool, field2: bool },
+}