Fix issue with missing built-in image of the epub generated

Author: morikat

ebook/build.sh

@@ -41,6 +41,10 @@ cat <<__METADATA__ > metadata.txt
 <dc:title>$MSG_TITLE</dc:title>
 __METADATA__
 
+mkdir -p $TMP/images
+cp -r $WORKDIR/images/* $TMP/images/
+ls [0-9]*.html | xargs sed -i "s/png?raw=true/png/g"
+
 pandoc --reference-links -S --toc -f html -t epub --epub-metadata=metadata.txt --epub-cover-image="$WORKDIR/../images/cover.png" -o "$WORKDIR/../build-web-application-with-golang.epub" `ls [0-9]*.html | sort`
 
 echo "$MSG_SUCCESSFULLY_GENERATED"