Add Dockerfile for arm64 (#762)

Dockerfile.arm64

@@ -0,0 +1,23 @@
+FROM alpine:3.17 as nim
+LABEL maintainer="[email protected]"
+
+RUN apk --no-cache add gcc git libc-dev libsass-dev "nim=1.6.8-r0" nimble pcre
+
+WORKDIR /src/nitter
+
+COPY nitter.nimble .
+RUN nimble install -y --depsOnly
+
+COPY . .
+RUN nimble build -d:danger -d:lto -d:strip \
+ && nimble scss \
+ && nimble md
+
+FROM alpine:3.17
+WORKDIR /src/
+RUN apk --no-cache add pcre ca-certificates
+COPY --from=nim /src/nitter/nitter ./
+COPY --from=nim /src/nitter/nitter.example.conf ./nitter.conf
+COPY --from=nim /src/nitter/public ./public
+EXPOSE 8080
+CMD ./nitter