use play symbols in jupyter chp

Author: trevorcampbell

source/_toc.yml

@@ -1,25 +1,25 @@
 format: jb-book
 root: index.md
 parts:
-#- caption: Front Matter
-#  chapters:
-#    - file: preface-text.md
-#    - file: foreword-text.md
-#    - file: acknowledgements.md
-#    - file: authors.md
+- caption: Front Matter
+  chapters:
+    - file: preface-text.md
+    - file: foreword-text.md
+    - file: acknowledgements.md
+    - file: authors.md
 - caption: Chapters
   numbered: 3
   chapters:
-    #- file: intro.md
-    #- file: reading.md
-    #- file: wrangling.md
-    #- file: viz.md
-    #- file: classification1.md
-    #- file: classification2.md
-    #- file: regression1.md
-    #- file: regression2.md
-    #- file: clustering.md
-    #- file: inference.md
-    #- file: jupyter.md
-    #- file: version-control.md
+    - file: intro.md
+    - file: reading.md
+    - file: wrangling.md
+    - file: viz.md
+    - file: classification1.md
+    - file: classification2.md
+    - file: regression1.md
+    - file: regression2.md
+    - file: clustering.md
+    - file: inference.md
+    - file: jupyter.md
+    - file: version-control.md
     - file: setup.md

source/jupyter.md

@@ -134,7 +134,7 @@ To run a code cell independently, the cell needs to first be activated. This
 is done by clicking on it with the cursor. Jupyter will indicate a cell has been
 activated by highlighting it with a blue rectangle to its left. After the cell
 has been activated ({numref}`activate-and-run-button`), the cell can be run by either pressing
-the **Run** (▸) button in the toolbar, or by using a keyboard shortcut of
+the **Run** (⏵) button in the toolbar, or by using a keyboard shortcut of
 `Shift + Enter`.
 
 ```{figure} img/jupyter/activate-and-run-button-annotated.png
@@ -231,7 +231,7 @@ To edit a Markdown cell in Jupyter, you need to double click on the cell. Once
 you do this,  the unformatted (or *unrendered*) version of the text will be
 shown ({numref}`markdown-cell-not-run`). You
 can then use your keyboard to edit the text. To view the formatted
-(or *rendered*) text ({numref}`markdown-cell-run`), click the **Run** (▸) button in the toolbar,
+(or *rendered*) text ({numref}`markdown-cell-run`), click the **Run** (⏵) button in the toolbar,
 or use the `Shift + Enter` keyboard shortcut.
 
 ```{figure} img/jupyter/markdown-cell-not-run.png
@@ -285,7 +285,7 @@ As you might know (or at least imagine) by now, Jupyter notebooks are great for
 interactively editing, writing and running Python code; this is what they were
 designed for! Consequently, Jupyter notebooks are flexible in regards to code
 cell execution order. This flexibility means that code cells can be run in any
-arbitrary order using the **Run** (▸) button. But this flexibility has a downside:
+arbitrary order using the **Run** (⏵) button. But this flexibility has a downside:
 it can lead to Jupyter notebooks whose code cannot be executed in a linear
 order (from top to bottom of the notebook). A nonlinear notebook is problematic
 because a linear order is the conventional way code documents are run, and
@@ -294,7 +294,7 @@ code is used in some automated process, it will need to run in a linear order,
 from top to bottom of the notebook.
 
 The most common way to inadvertently create a nonlinear notebook is to rely solely
-on using the (▸) button to execute cells. For example,
+on using the (⏵) button to execute cells. For example,
 suppose you write some Python code that creates a Python object, say a variable named
 `y`. When you execute that cell and create `y`, it will continue
 to exist until it is deliberately deleted with Python code, or when the Jupyter