install node.js in docker container (#87)

see yt-dlp/yt-dlp#15012

With the release of yt-dlp version 2025.11.12, external JavaScript runtime support has arrived.
All users who intend to use yt-dlp with YouTube are strongly encouraged to install one of the supported JS runtimes.

Author: magicxor

Dockerfile

@@ -20,8 +20,13 @@ ENV RATE_LIMIT_WINDOW_MINUTES=1
 
 RUN apt-get update && \
     apt-get upgrade -y && \
+    apt-get install -y curl ffmpeg unzip && \
+    curl -o- https://fnm.vercel.app/install | bash
+SHELL ["/bin/bash", "--login", "-c"]
+RUN fnm install --lts && \
+    node -v && \
+    npm -v  && \
     python -m pip install --upgrade pip && \
-    apt-get install -y curl ffmpeg && \
     apt-get clean && rm -rf /var/lib/apt/lists/* && \
     mkdir /app