doc(example.dae): add node selection by tag (#44)

* doc: add node selection by tag

* fix: fix syntax

* fix: fix formatting

example.dae

@@ -72,6 +72,8 @@ node {
     # Support socks5, http, https, ss, ssr, vmess, vless, trojan, trojan-go
     'socks5://localhost:1080'
     mylink: 'ss://LINK'
+    node1: 'vmess://LINK'
+    node2: 'vless://LINK'
 }
 
 # See https://github.com/daeuniverse/dae/blob/main/docs/dns.md for full examples.
@@ -119,6 +121,8 @@ group {
     group2 {
         # Filter nodes from the global node pool defined by the subscription and node section above.
         filter: subtag(regex: '^my_', another_sub) && !name(keyword: 'ExpireAt:')
+        # Filter nodes from the global node pool defined by tag
+        #filter: name(node1, node2)
 
         # Select the node with min average of the last 10 latencies from the group for every connection.
         policy: min_avg10