Add dockerfile for build container

Dockerfile

@@ -0,0 +1,11 @@
+FROM debian:sid
+
+RUN apt-get -y update && DEBIAN_FRONTEND=noninteractive apt-get -y install html2text curl
+
+RUN curl --location "https://golang.org/dl/go1.18.linux-amd64.tar.gz" | tar -xzf - -C /usr/local/
+
+ENV PATH="/usr/local/go/bin:/usr/local/gopkg/bin:${PATH}"
+
+RUN GOPATH=/usr/local/gopkg go install github.com/ericchiang/pup@latest
+
+RUN rm -rvf /usr/local/go