message: document allowDiskUse option as being supported in 4.4+
diff: @@ -42,6 +42,8 @@ class MONGOCXX_API find {
  /// This option is sent only if the caller explicitly provides a value. The default
  /// is to not send a value.
  ///
  + /// This option may only be used with MongoDB version 4.4 or later.
  + ///
  /// @param allow_disk_use
  /// Whether to allow writing temporary files on the server.
  ///
  @@ -55,6 +57,8 @@ class MONGOCXX_API find {
  ///
  /// Gets the current setting for allowing disk use on the server.
  ///
  + /// This option may only be used with MongoDB version 4.4 or later.
  + ///
  /// @return Whether disk use on the server is allowed.
  ///
  const stdx::optional<bool>& allow_disk_use() const;
  