correct two references to changed name of jss intro vignette

Author: eddelbuettel

vignettes/Rcpp-attributes.Rmd

@@ -326,7 +326,7 @@ requirements to be correctly handled:
 - Be defined in the global namespace (i.e. not within a C++ namespace declaration)
 - Have a return type that is either void or compatible with `Rcpp::wrap`
   and parameter types that are compatible with `Rcpp::as` (see sections
-  3.1 and 3.2 of the '\textsl{Rcpp-introduction}' vignette for more details).
+  3.1 and 3.2 of the '\textsl{Rcpp-jss-2011}' vignette for more details).
 - Use fully qualified type names for the return value and all parameters.
   Rcpp types may however appear without a namespace qualifier (i.e.
   `DataFrame` is okay as a type name but `std::string` must be

vignettes/Rcpp-modules.Rmd

@@ -97,7 +97,7 @@ by the \pkg{Rcpp} package and its underlying \proglang{C++} library
 \proglang{R} and \proglang{C++} integration by replacing the traditional
 \proglang{R} Application Programming Interface (API) described in
 `\textsl{Writing R Extensions}' \citep{R:Extensions} with a consistent set of \proglang{C++}
-classes. The '\textsl{Rcpp-introduction}' vignette \citep{CRAN:Rcpp,JSS:Rcpp} describes the API and
+classes. The '\textsl{Rcpp-jss-2011}' vignette \citep{CRAN:Rcpp,JSS:Rcpp} describes the API and
 provides an introduction to using \pkg{Rcpp}.
 
 These \pkg{Rcpp} facilities offer a lot of assistance to the programmer