Posts can contain live R code. A chunk like the one below runs when the post is rendered, and its output is cached so it doesn’t rerun unless the post changes:

library(ggplot2)

ggplot(mtcars, aes(wt, mpg)) +
  geom_point(colour = "#970909") +
  theme_minimal()

(Write it as {r} instead of r after the backticks to make it execute.)