use plotly; fix bitrot

quarto/derivatives/lhospitals_rule.qmd

@@ -9,8 +9,8 @@ This section uses these add-on packages:
 ```{julia}
 using CalculusWithJulia
 using Plots
+plotly()
 using SymPy
-
 ```
 
 
@@ -245,6 +245,7 @@ A first proof of L'Hospital's rule takes advantage of Cauchy's [generalization](
 #| echo: false
 #| cache: true
 using Roots
+gr()
 let
 ## {{{lhopitals_picture}}}
 
@@ -293,7 +294,7 @@ imgfile = tempname() * ".gif"
 gif(anim, imgfile, fps = 1)
 
 
-plotly()
+    plotly()
     ImageFile(imgfile, caption)
 end
 ```