[doc] Add PNG logo for OpenGraph

OpenGraph extension uses html_logo to generate previews
by default but it does not support SVG. Adding a PNG
version to use for social cards.

Bug: T333796
Change-Id: I4f85e5c2a8ae62f95f0671664758bc87dca29e82
---
A docs/_static/Pywikibot_MW_gear_icon.png
M docs/conf.py
2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/docs/_static/Pywikibot_MW_gear_icon.png b/docs/_static/Pywikibot_MW_gear_icon.png
new file mode 100644
index 0000000..c4292b2
--- /dev/null
+++ b/docs/_static/Pywikibot_MW_gear_icon.png
Binary files differ
diff --git a/docs/conf.py b/docs/conf.py
index 1a167d7..d1fb603 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -175,6 +175,13 @@
 #
 html_logo = '_static/Pywikibot_MW_gear_icon.svg'
 
+# Use a PNG version of the logo in OpenGraph social cards
+# (needed because SVG is not supported)
+
+ogp_social_cards = {
+    'image': '_static/Pywikibot_MW_gear_icon.png',
+}
+
 # The name of an image file (relative to this directory) to use as a favicon of
 # the docs. This file should be a Windows icon file (.ico) being 16x16 or 32x32
 # pixels large.

