add docker + workflow

Dockerfile

@@ -0,0 +1,19 @@
+FROM rust:buster as builder
+
+COPY . /app
+WORKDIR /app
+
+RUN cargo build --release
+
+FROM archlinux
+
+# Install dependencies for yt-dlp and ffmpeg
+RUN pacman -Syu --noconfirm && \
+    pacman -S --noconfirm ca-certificates ffmpeg yt-dlp && \
+    rm -rf /var/cache/pacman/pkg/*
+
+COPY --from=builder /app/target/release/hoard /hoard
+
+WORKDIR /
+
+CMD ["/hoard"]