Freeze Quarto execution & enable Chinese fonts

Set execute.freeze to true in r-and-rmarkdown/_quarto.yml to freeze rendered outputs, and add an R code chunk calling showtext::showtext_auto() to r-and-rmarkdown/lectures/lecture2-data-viz.qmd so Chinese characters render correctly in plots.

Author: ShixiangWang

r-and-rmarkdown/_quarto.yml

@@ -132,7 +132,7 @@ format:
     link-external-newwindow: true
 
 execute:
-  freeze: false
+  freeze: true
   echo: true
 
 bibliography: references.bib

r-and-rmarkdown/lectures/lecture2-data-viz.qmd

@@ -47,6 +47,11 @@ install.packages("tidyverse")
 library(tidyverse)
 ```
 
+```{r}
+# 支持图片显示中文字体
+showtext::showtext_auto()
+```
+
 ---
 
 ## 2. dplyr数据处理