Update Global options documentation - v2.6.3

Add the recently introduced `name` option to the global `servers` directive

src/docs/markdown/caddyfile/options.md

@@ -105,6 +105,7 @@ Possible options are:
 			write       <duration>
 			idle        <duration>
 		}
+		name main
 		metrics
 		max_header_size <size>
 		log_credentials
@@ -409,6 +410,10 @@ Enables Prometheus metrics collection; necessary before scraping metrics. Note t
 The maximum size to parse from a client's HTTP request headers. It accepts all formats supported by [go-humanize](https://github.com/dustin/go-humanize/blob/master/bytes.go).
 
 
+##### `name`
+
+A custom name to assign to this server. Usually helpful to identify a server by its name in logs and metrics. If not set, Caddy will define it dynamically using a `srvX` pattern, where `X` starts with 0 and increments based on the number of servers in the config.
+
 ##### `log_credentials`
 
 Since Caddy v2.5, by default, headers with potentially sensitive information (`Cookie`, `Set-Cookie`, `Authorization` and `Proxy-Authorization`) will be logged with empty values in access logs (see the [`log` directive](/docs/caddyfile/directives/log)).