get it working on M2 Mac

In addition, get it working on Podman.

Discussion of the Apple silicon M1/M2 arm64 chip:
rocker-org/rocker-versioned2#144

Dockerfile

@@ -1,3 +1,3 @@
-FROM rocker/tidyverse:3.5.0
+FROM rocker/tidyverse:4.2.2
 ADD . /
 RUN ./run.sh

README.md

@@ -2,10 +2,13 @@
 
 Just a little R project using ggplot2.
 
+Most recently tested using Podman on an M2 Mac.
+
 ```
 docker rm extract
-docker build -t pdurbin/notice .
-docker create --name extract pdurbin/notice
-docker cp extract:/results/figure.png /tmp
-docker cp extract:/results/figure.svg /tmp
+docker build --platform linux/x86_64 -t pdurbin/notice .
+docker create --platform linux/x86_64 --name extract pdurbin/notice
+mkdir /tmp/out
+docker cp extract:/results/figure.png /tmp/out
+#docker cp extract:/results/figure.svg /tmp
 ```

code/plot.R

@@ -35,4 +35,4 @@ ggplot(renewal, aes(x = Events)) +
 	  )
 
 ggsave(path = "results", filename = "figure.png", width = 7, height = 3)
-ggsave(path = "results", filename = "figure.svg", width = 7, height = 3)
+#ggsave(path = "results", filename = "figure.svg", width = 7, height = 3)