fix broken pkgdown link

Author: t-kalinowski

pkgdown/_pkgdown.yml

@@ -31,7 +31,7 @@ navbar:
         - text: "Python Subclasses"
           href: articles/python_subclasses.html
         - text: "Making New Layers and Models via Subclassing"
-          href: articles/guides/making_new_layers_and_models_via_subclassing.Rmd
+          href: articles/guides/making_new_layers_and_models_via_subclassing.html
         - text: "Customizing what happens in fit"
           href: articles/guides/customizing_what_happens_in_fit.html
         - text: "--------------------------"

vignettes/guides/customizing_what_happens_in_fit.Rmd

@@ -30,6 +30,11 @@ editor_options:
 
 ```{r setup, include = FALSE}
 library(keras)
+knitr::opts_chunk$set(
+  eval = FALSE,
+  collapse = TRUE,
+  comment = "#>"
+)
 ```
 
 ## Summary

vignettes/guides/writing_your_own_callbacks.Rmd

@@ -19,9 +19,11 @@ to visualize training progress and results with TensorBoard, or
 In this guide, you will learn what a Keras callback is, what it can do, and how you can
 build your own. We provide a few demos of simple callback applications to get you
 started.
-```
 
+```{r, include=FALSE}
+knitr::opts_chunk$set(comment = NA, eval = FALSE)
 ```
+
 ## Setup
 ```{R}
 library(tensorflow)