Merging to release-5.8: [DX-2045] docs: clarify TYK_GW_MAXIDLECONNSPERHOST default value and recommendation (#1136)

[DX-2045] docs: clarify TYK_GW_MAXIDLECONNSPERHOST default value and recommendation (#1136)

Author: buger

snippets/gateway-config.mdx

@@ -908,7 +908,7 @@ Maximum idle connections, per API, between Tyk and Upstream. By default not limi
 ENV: <b>TYK_GW_MAXIDLECONNSPERHOST</b><br />
 Type: `int`<br />
 
-Maximum idle connections, per API, per upstream, between Tyk and Upstream. Default:100
+Maximum idle connections, per API, per upstream, between Tyk and Upstream. A value of `0` will use the default from the Go standard library, which is 2 connections. Tyk recommends setting this value to `500` for production environments.
 
 ### max_conn_time
 ENV: <b>TYK_GW_MAXCONNTIME</b><br />