fix nginx config for single-page app

automation/roles/nginx/templates/site_node.conf.j2

@@ -2,8 +2,11 @@ server {
     server_name {{ server_name }};
     listen {{ ssl_port }} ssl http2;
 
+    root  /home/bubble/site/;
+    index index.html;
+
     location / {
-        root /home/bubble/site/;
+        try_files $uri /index.html =404;
     }
 
     location /api {

automation/roles/nginx/templates/site_node_alias.conf.j2

@@ -2,8 +2,11 @@ server {
     server_name {{ server_alias }};
     listen {{ ssl_port }} ssl http2;
 
+    root  /home/bubble/site/;
+    index index.html;
+
     location / {
-        root /home/bubble/site/;
+        try_files $uri /index.html =404;
     }
 
     location /api {

automation/roles/nginx/templates/site_sage.conf.j2

@@ -2,8 +2,11 @@ server {
     listen 80;
     server_name {{ server_name }};
 
+    root  /home/bubble/site/;
+    index index.html;
+
     location / {
-        root /home/bubble/site/;
+        try_files $uri /index.html =404;
     }
 
     location /api {

automation/roles/nginx/templates/site_sage_alias.conf.j2

@@ -2,8 +2,11 @@ server {
     listen 80;
     server_name {{ server_alias }};
 
+    root  /home/bubble/site/;
+    index index.html;
+
     location / {
-        root /home/bubble/site/;
+        try_files $uri /index.html =404;
     }
 
     location /api {