change jpegs to pngs in intro chp

Author: trevorcampbell

source/intro.Rmd

@@ -262,7 +262,7 @@ to read data into R.
 (ref:img-read-csv) Syntax for the `read_csv` function.
 
 ``` {r img-read-csv, echo = FALSE, message = FALSE, warning = FALSE, fig.align = "center", fig.cap = "(ref:img-read-csv)", fig.retina = 2, out.width="100%", fig.pos = "H", out.extra=""}
-image_read("img/intro/read_csv_function.jpeg") |>
+image_read("img/intro/read_csv_function.png") |>
   image_crop("1625x1900")
 ```
 
@@ -400,7 +400,7 @@ code we have already written.
 (ref:img-filter) Syntax for the `filter` function.
 
 ```{r img-filter, echo = FALSE, message = FALSE, warning = FALSE, fig.align = "center", fig.cap = "(ref:img-filter)", fig.retina = 2, out.width="100%"}
-image_read("img/intro/filter_function.jpeg") |>
+image_read("img/intro/filter_function.png") |>
   image_crop("1625x1900")
 ```
 
@@ -436,7 +436,7 @@ in the next step of the analysis!
 (ref:img-select) Syntax for the `select` function.
 
 ``` {r img-select, echo = FALSE, message = FALSE, warning = FALSE, fig.align = "center", fig.cap = "(ref:img-select)", out.width="100%", fig.retina = 2}
-image_read("img/intro/select_function.jpeg") |>
+image_read("img/intro/select_function.png") |>
   image_crop("1625x1900")
 ```
 
@@ -468,7 +468,7 @@ so we pass the column to the `desc` function before using it as an argument.
 (ref:img-arrange) Syntax for the `arrange` function.
 
 ``` {r img-arrange, echo = FALSE, message = FALSE, warning = FALSE, fig.align = "center", fig.cap = "(ref:img-arrange)", out.width="100%", fig.retina = 2}
-image_read("img/intro/arrange_function.jpeg") |>
+image_read("img/intro/arrange_function.png") |>
   image_crop("1625x1900")
 ```
 
@@ -555,7 +555,7 @@ generated by following the instructions in Figure \@ref(fig:img-ggplot).
 (ref:img-ggplot) Creating a bar plot with the `ggplot` function.
 
 ```{r img-ggplot, echo = FALSE, message = FALSE, warning = FALSE, fig.align = "center", fig.cap = "(ref:img-ggplot)", out.width="100%", fig.retina = 2}
-image_read("img/intro/ggplot_function.jpeg") |>
+image_read("img/intro/ggplot_function.png") |>
   image_crop("1625x1900")
 ```