update issue template

Author: eddelbuettel

.github/ISSUE_TEMPLATE.md

@@ -5,12 +5,12 @@ Make use of the *Preview* tab just above!
 
 #### Before filing an issue with Rcpp, please ensure that you
 
-- searched the mailing list archives for the [rcpp-devel](https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel) list for the question I want to ask about; you can do this at at Google with the `site:` qualifier as in this simple example: `site:lists.r-forge.r-project.org rcpp-devel how do I declare a const vector`;
+- searched the mailing list archives for the [rcpp-devel](https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel) list for the question you want to ask about; you can do this at at Google with the `site:` qualifier as in this simple example: `site:lists.r-forge.r-project.org rcpp-devel how do I declare a const vector`;
 
 - searched the [StackOverflow](https://stackoverflow.com/) `[rcpp]` tag _e.g._ via `[rcpp] how do I sample a vector`;
 
 - searched existing [GitHub issues](https://github.com/RcppCore/Rcpp/issues) which can be searched among open and closed ones;
 
 - read the [Contributing](https://github.com/RcppCore/Rcpp/blob/master/Contributing.md) page for details on preferred reporting and style;
 
-If you have the above, remove the text above and provide a [`Minimally Complete and Reproducible Example`](https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example), the output of `sessionInfo()` plus relevant information about the C++ compiler.
+If you have the above, remove the text above and provide a [Minimally Complete and Verifiable Example (MCVE)](https://stackoverflow.com/help/minimal-reproducible-example), the output of `sessionInfo()` plus relevant information about the C++ compiler.  All this takes a little bit of effort---but greatly increases your chances of getting an applicable and helpful follow-up in return.