Enable deploying code for the raspberry pis

Also, sets up a systemd service to start all the code.

Change-Id: If993426b36d0910497579ad86e330699f8a7d2e7
diff --git a/y2020/www/BUILD b/y2020/www/BUILD
index c280e91..292618b 100644
--- a/y2020/www/BUILD
+++ b/y2020/www/BUILD
@@ -1,5 +1,6 @@
 load("@build_bazel_rules_typescript//:defs.bzl", "ts_library")
 load("@build_bazel_rules_nodejs//:defs.bzl", "rollup_bundle")
+load("//frc971/downloader:downloader.bzl", "aos_downloader_dir")
 
 ts_library(
     name = "main",
@@ -44,3 +45,14 @@
     cmd = "cp $(location @com_github_google_flatbuffers//:flatjs) $@",
     visibility = ["//y2020:__subpackages__"],
 )
+
+aos_downloader_dir(
+    name = "www_files",
+    srcs = [
+        ":files",
+        ":flatbuffers",
+        ":main_bundle",
+    ],
+    dir = "www",
+    visibility = ["//visibility:public"],
+)