Add info on gethostip's new api to docs

Author: rsp

README.md

@@ -13,7 +13,6 @@ Some of those scripts were written for
 * [Make a sound once process is complete](https://askubuntu.com/questions/277215/make-a-sound-once-process-is-complete/604116#604116) (on [Ask Ubuntu](https://askubuntu.com/users/11582/rsp))
 * [How can I get my external IP address in bash?](https://unix.stackexchange.com/questions/22615/how-can-i-get-my-external-ip-address-in-bash/194136#194136) (on [Unix & Linux](https://unix.stackexchange.com/users/23774/rsp))
 * [How do I find my internal ip address?](https://askubuntu.com/questions/430853/how-do-i-find-my-internal-ip-address/604691#604691) (on [Ask Ubuntu](https://askubuntu.com/users/11582/rsp))
-
 Some are just for my own conveniece. Maybe they would be useful to someone else.
 
 Functions
@@ -50,7 +49,8 @@ Source: https://rawgit.com/rsp/scripts/master/internalip
 
 Get internal IP address used for outgoing Internet connections.
 
-TARGET is an IP address, `8.8.8.8` by default.
+TARGET is an IP address, `8.8.8.8` by default,
+or a host name (if `gethostip` or `getent` are available on the system).
 
 See [internalip.md](internalip.md) for more info.
 

internalip.md

@@ -12,6 +12,7 @@ that would be used to connect to a given target.
 
 The TARGET is optional and by default it is `8.8.8.8`
 (which is the [Google's public DNS resolver](https://developers.google.com/speed/public-dns/docs/using)).
+It can be an IP address or a host name (if `gethostip` or `getent` are available on the system).
 
 Note: this is not necessarily the same IP as the public IP that you visible under while connecting to the Internet
 (for that use [externalip](externalip.md)).