Support multi-plot in Rmd

[jooyoungseo]

In the following example, only the last plot gets the interactivity. We have to support multi-plots in Rmd.

Reprex

test.Rmd:

---
output: html_document
---

```{r}
library(tidyverse)
library(maidr)

g <- ggplot(mpg, aes(class)) +
  geom_bar()
maidr(g)$maidr_widget
```


```{r}
g2 <- ggplot(starwars, aes(height, mass)) +
  geom_point() +
  geom_smooth(method = "loess")
maidr(g2)$maidr_widget
```