Add MMDB download to Dockerfile (#11)

Dockerfile

@@ -7,6 +7,18 @@ COPY . ./
 RUN go get ./...
 RUN go build -v -o /livestream ./...
 
+# Fetch the GeoLite2-City database that will be used for IP geolocation within Django.
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+    "ca-certificates" \
+    "curl" \
+    "brotli" \
+    && \
+    rm -rf /var/lib/apt/lists/* && \
+    mkdir share && \
+    ( curl -s -L "https://mmdbcdn.posthog.net/" --http1.1 | brotli --decompress --output=/mmdb.db ) && \
+    chmod -R 755 /mmdb.db
+
 FROM ubuntu
-COPY --from=builder /livestream /livestream
+COPY --from=builder /livestream /mmdb.db /
 CMD ["/livestream"]