Merge pull request #973 from gwenn/doc_cfg

Use #[doc(cfg)]

src/statement.rs

@@ -776,6 +776,7 @@ impl Statement<'_> {
     /// Returns a string containing the SQL text of prepared statement with
     /// bound parameters expanded.
     #[cfg(feature = "modern_sqlite")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "modern_sqlite")))]
     pub fn expanded_sql(&self) -> Option<String> {
         self.stmt
             .expanded_sql()