Add docs about getting an IP address of a client who initiated a request (#1495)
Add docs about getting an IP address of a client who initiated a request (#1495)

Modifications:
- Add `Getting an IP address of a client who initiated a request` section to `server-basics.rst`.
line/armeria,anuraaga/armeria,minwoox/armeria,kojilin/armeria,trustin/armeria,trustin/armeria,anuraaga/armeria,line/armeria,kojilin/armeria,kojilin/armeria,minwoox/armeria,minwoox/armeria,line/armeria,trustin/armeria,anuraaga/armeria,trustin/armeria,anuraaga/armeria,line/armeria,kojilin/armeria,minwoox/armeria,trustin/armeria,kojilin/armeria,minwoox/armeria,anuraaga/armeria,trustin/armeria,kojilin/armeria,line/armeria,line/armeria,anuraaga/armeria,minwoox/armeria