Update node version for doc building

Author: katalinic-gc

docs/Dockerfile

@@ -9,7 +9,7 @@ RUN apt-get update && apt-get install -y \
     git \
     curl \
     gnupg
-RUN curl -sL https://deb.nodesource.com/setup_14.x  | bash -
+RUN curl -sL https://deb.nodesource.com/setup_18.x  | bash -
 RUN apt-get -y install nodejs
 RUN npm install npm@latest -g && \
     npm install n -g && \