Added Dockerfile for building the blog container

Signed-off-by: Louis Vallat <louis@louis-vallat.xyz>

Dockerfile

@@ -0,0 +1,16 @@
+FROM alpine AS builder
+
+WORKDIR /root
+
+COPY src ./src
+COPY ssg5 .
+
+RUN apk --no-cache add gcc git make musl-dev && \
+    git clone https://github.com/kristapsdz/lowdown.git && \
+    cd lowdown && ./configure && make && make regress && make install && cd .. && \
+    chmod u+x ./ssg5 && mkdir dst && \
+    ./ssg5 ./src/ ./dst/ "Blog" "blog.louis-vallat.xyz"
+
+FROM nginx
+
+COPY --from=builder /root/dst /usr/share/nginx/html