docs: Minor updates to file_server and reverse_proxy

src/docs/markdown/caddyfile/directives/reverse_proxy.md

@@ -204,10 +204,10 @@ transport http {
     tls_server_name <sni>
 	keepalive [off|<duration>]
 	keepalive_idle_conns <max_count>
+    keepalive_idle_conns_per_host <count>
     versions <versions...>
     compression off
     max_conns_per_host <count>
-    max_idle_conns_per_host <count>
 }
 ```
 
@@ -226,10 +226,10 @@ transport http {
 - **tls_server_name** sets the ServerName (SNI) to put in the ClientHello; only needed if the remote server requires it.
 - **keepalive** is either `off` or a [duration value](/docs/conventions#durations) that specifies how long to keep connections open.
 - **keepalive_idle_conns** defines the maximum number of connections to keep alive.
+- **keepalive_idle_conns_per_host** if non-zero, controls the maximum idle (keep-alive) connections to keep per-host. Default: `32`
 - **versions** allows customizing which versions of HTTP to support. As a special case, "h2c" is a valid value which will enable cleartext HTTP/2 connections to the upstream (however, this is a non-standard feature that does not use Go's default HTTP transport, so it is exclusive of other features; subject to change or removal). Default: `1.1 2`, or if scheme is `h2c://`, `h2c 2`
 - **compression** can be used to disable compression to the backend by setting it to `off`.
 - **max_conns_per_host** optionally limits the total number of connections per host, including connections in the dialing, active, and idle states. Has no limit by default.
-- **max_idle_conns_per_host** if non-zero, controls the maximum idle (keepalive) connections to keep per-host. Default: `2`