chore: Fix dhcp client link

Author: rsmarples

Diff for: README.md

@@ -37,7 +37,7 @@ Here's some reasons:
 
 The last point is quite important, especially when running VPN systems.
 Take the following resolv.conf files which have been generated by a
-[DHCP client](../dhcpcd) and sent to resolvconf:
+[DHCP client](https://github.com/NetworkConfiguration/dhcpcd) and sent to resolvconf:
 
 ```
 # resolv.conf from bge0