Update production configurations + README for v2.3

* Refactor production nginx configuration files
* Update README for new networks, SQL, etc.

production/nginx/http-proxy-cache.conf

@@ -0,0 +1,4 @@
+# proxy cache
+proxy_cache_path /var/cache/nginx/services keys_zone=services:20m levels=1:2 inactive=600s max_size=100m;
+proxy_cache_path /var/cache/nginx/markets keys_zone=markets:20m levels=1:2 inactive=600s max_size=100m;
+types_hash_max_size 2048;