Add gzip support to the sample nginx configuration

Without gzip explicitly enabled, load times suffer from transferring
over a megabyte of plaintext javascript. With gzip enabled, the bundle
is down to about 300K, and loads much faster.

This change does not enable gzip on files that are already compressed,
so images, fonts, and videos will be sent without the CPU overhead.

support/nginx/peertube

@@ -37,6 +37,11 @@ server {
   # resolver $DNS-IP-1 $DNS-IP-2 valid=300s;
   # resolver_timeout 5s;
 
+  # Enable compression for JS/CSS/HTML and JSON, for improved client load times
+  gzip on;
+  gzip_types text/plain text/css text/html application/javascript application/json;
+  gzip_vary on;
+
   add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload";
 
   access_log /var/log/nginx/peertube.example.com.access.log;