Merge pull request #720 from nextcloud/bugfix/addXindyToDocumentationImage

add xindy to documentation docker image

Author: mgallien

documentation/Dockerfile

@@ -3,5 +3,5 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y python3-
     python3-pip texlive-fonts-recommended latexmk \
     texlive-latex-extra texlive-latex-recommended make php-cli php-xml composer \
     texlive-xetex texlive-fonts-extra-links texlive-fonts-extra \
-    nodejs npm libgbm1 libasound2 wget
+    nodejs npm libgbm1 libasound2 wget xindy