fix: arm dockerfile build step

dev/build-arm/Dockerfile

+# =========================
+# --- BUILD NPM MODULES ---
+# =========================
+FROM node:12.13-alpine AS build
+
+RUN apk add yarn g++ make python --no-cache
+
+WORKDIR /wiki
+
+COPY ./package.json ./package.json
+
+RUN yarn --production --frozen-lockfile --non-interactive --network-timeout 100000
+
+# ===============
+# --- Release ---
+# ===============
 FROM node:12.13-alpine
 LABEL maintainer="requarks.io"
 
@@ -9,6 +25,7 @@ RUN apk add bash curl git openssh gnupg sqlite --no-cache && \
 WORKDIR /wiki
 
 COPY --chown=node:node ./build/assets ./assets
+COPY --chown=node:node --from=build /wiki/node_modules ./node_modules
 COPY --chown=node:node ./server ./server
 COPY --chown=node:node ./build/server/views ./server/views
 COPY --chown=node:node ./dev/build/config.yml ./config.yml
@@ -16,8 +33,6 @@ COPY --chown=node:node ./dev/docker-common/wait.sh ./wait.sh
 COPY --chown=node:node ./package.json ./package.json
 COPY --chown=node:node ./LICENSE ./LICENSE
 
-RUN yarn --production --frozen-lockfile --non-interactive --network-timeout 100000
-
 USER node
 
 EXPOSE 3000