feat(security): add security headers documentation and update nginx configuration

Dockerfile

@@ -90,6 +90,7 @@ USER nginx
 COPY --chown=nginx:nginx --from=builder /app/dist /usr/share/nginx/html${BASE_URL%/}
 COPY --chown=nginx:nginx nginx.conf /etc/nginx/nginx.conf
 COPY --chown=nginx:nginx --from=builder /app/security-headers.conf /etc/nginx/security-headers.conf
+COPY --chown=nginx:nginx --from=builder /app/security-headers-docs.conf /etc/nginx/security-headers-docs.conf
 COPY --chown=nginx:nginx --chmod=755 nginx-ipv6.sh /docker-entrypoint.d/99-disable-ipv6.sh
 RUN mkdir -p /etc/nginx/tmp && chown -R nginx:nginx /etc/nginx/tmp