Add a very basic example module and build it in the CI

Dockerfile.buildexamples

@@ -0,0 +1,15 @@
+FROM wiiuenv/devkitppc:20211229
+
+WORKDIR build
+COPY . .
+RUN make clean && make && mkdir -p /artifacts/wums && cp -r lib /artifacts/wums && cp -r include /artifacts/wums && cp -r share /artifacts/wums
+WORKDIR /artifacts
+
+FROM scratch as libwums
+COPY --from=0 /artifacts /artifacts
+
+FROM wiiuenv/devkitppc:20211229
+
+COPY --from=libwums /artifacts $DEVKITPRO
+
+WORKDIR project