Partial fix for PDF doc build (#2044)

* Add pngcrushed 'Image Not Available' placeholder

* Fix absent camo.github usercontent for Truple Vision on Game Jam 2020 page

* Replace FlaPy bird image with non-404

* Fix Two Worlds image for sample games

* Allow PDF to build by converting .gif images

* Add requirements notes on PDF built to CONTRIBUtING.md

* Add install size flag

* Add link targets for BoxHead

* Remove image + fix typo

* Remove unused image_not_available.png

CONTRIBUTING.md

@@ -155,6 +155,37 @@ You can now open http://localhost:8000 in your browser to preview the doc.
 
 Be sure to re-run build & refresh to update after making changes!
 
+#### Building PDFs
+
+It is also possible to build a PDF of Arcade's documentation. This is
+more complicated than the HTML doc because it requires
+[LaTex](https://www.latex-project.org/), a powerful documentation
+language.
+
+##### Installing
+
+On Linux distros based on Debian and Ubuntu, you may need to install
+the following packages to build PDFs:
+
+``console
+sudo apt install latexmk
+sudo apt install texlive-latex-extra 
+``
+To reduce the large (300 MB+) install size of the second package, you
+may be able to use the `--no-install-recommends` flag.
+
+Other platforms may require different install steps.
+
+##### Building
+
+Once you have LaTeX and extra required configs installed,
+run the following:
+
+```console
+./make.py latexpdf
+```
+
+
 ## Optional: Improve Ergonomics on Mac and Linux
 
 ### make.py shorthand

doc/conf.py

@@ -58,6 +58,7 @@
 extensions = [
     'sphinx.ext.autodoc',
     'sphinx.ext.napoleon',
+    'sphinx.ext.imgconverter',  # Converts .gif for PDF doc build
     'sphinx.ext.doctest',
     'sphinx.ext.intersphinx',
     'sphinx.ext.todo',

doc/example_code/game_jam_2020.rst

@@ -30,11 +30,7 @@ Here are the games that made it to the top 10:
 
     2nd Place: `Triple Blocks <https://github.com/python-discord/game-jam-2020/tree/master/Finalists/gamer_gang>`_
 
-.. figure:: https://camo.githubusercontent.com/f28f09b33244a7db72df7b4985791d89358f8d88/68747470733a2f2f63646e2e646973636f72646170702e636f6d2f6174746163686d656e74732f3639333137373530373638333336393031302f3730343030363031343535343437323439382f756e6b6e6f776e2e706e67
-    :target: https://github.com/python-discord/game-jam-2020/tree/master/Finalists/monkeys-and-frogs-on-fire
-    :width: 45%
-
-    3nd Place: `Triple Vision <https://github.com/python-discord/game-jam-2020/tree/master/Finalists/monkeys-and-frogs-on-fire>`_
+3rd Place: `Triple Vision <https://github.com/python-discord/game-jam-2020/tree/master/Finalists/monkeys-and-frogs-on-fire>`_
 
 .. figure:: https://raw.githubusercontent.com/python-discord/game-jam-2020/master/Finalists/KTGames/rd_images/OpeningScreen.png
     :target: https://github.com/python-discord/game-jam-2020/tree/master/Finalists/KTGames

doc/example_code/sample_games.rst

@@ -13,14 +13,18 @@ You also might want to check out sample Arcade games from:
 * :ref:`concept_games`
 * :ref:`platformer_tutorial`
 
-BoxHead
-~~~~~~~
+
+BoxHead Survivor
+~~~~~~~~~~~~~~~~
 
 .. image:: https://img.itch.zone/aW1hZ2UvMjM1MTM4Mi8xMzkyODQ1Ni5qcGc=/original/YI7uLX.jpg
    :width: 560px
 
-- GitHub:  Unchained112/BoxHead2D: A top-down shooter game dev with Python Arcade (github.com)
-- itch io:  BoxHead Survivor by Unchain (itch.io)
+A top-down 2D shooter game.
+
+* Playable builds at `itch.io <https://unchain112.itch.io/boxhead-survivor>`_
+* Source on `GitHub at Unchained112/BoxHead2D <https://github.com/Unchained112/BoxHead2D>`_
+
 
 Temporum
 ~~~~~~~~
@@ -197,7 +201,7 @@ Space Typer
 FlapPy Bird
 ~~~~~~~~~~~
 
-.. image:: https://camo.githubusercontent.com/f0e9f79d083289e7385a9af79231ba9cc07a10dd/68747470733a2f2f692e706f7374696d672e63632f665678394b736b672f53637265656e5f53686f745f323031382d30392d32375f61745f31322e31312e31395f414d2e706e67
+.. image:: https://camo.githubusercontent.com/b373859d570155b72030f36ae7ece8b9575bda6d45eb0695f5a060d3dfa27dab/68747470733a2f2f692e706f7374696d672e63632f665678394b736b672f53637265656e5f53686f745f323031382d30392d32375f61745f31322e31312e31395f414d2e706e67
 
 `FlapPy-Bird`_ - A bird-game clone.
 
@@ -230,7 +234,7 @@ Dungeon_, explore a maze picking up arrows and coins.
 Two Worlds
 ~~~~~~~~~~
 
-.. image:: https://camo.githubusercontent.com/bb2fb323ea9ab3f6041d3b72569a2d2360aa46ba07fe4cb3dbcd8248b3e8699d/68747470733a2f2f696d6775722e636f6d2f7356516e4331542e706e67
+.. image:: https://camo.githubusercontent.com/a74f38285980087502aec7795e10bec5869e71c840a35729fa37edf6ad17858d/68747470733a2f2f696d6775722e636f6d2f634372674171712e706e67
    :width: 75%
 
 `Two Worlds`_, a castle adventure with a dungeon and caverns underneath it.