It clearly says on the wikipedia page "The simplest way to compile a plugin
that doesn't rely on any custom include files is using the web compiler."
The plugin you are trying to compile does rely on custom include files.
So read the whole page and follow along.
You can find the list of all required custom include files on the github page of
smrpg.
In case you are not able to follow along here are the compiled files.
Read the
installation note on how to install smrpg.