etc/hosts/hostname: copy Debian behaviour as a good practice

etc/hosts/README.md

@@ -10,6 +10,7 @@ This file is DNS before DNS and legacy remain which is still used.
 
 - [`blocklist`](#blocklist)
 - [`dns`](#dns)
+- [`hostname`](#hostname)
 - [`hosts.arch`](#hostsarch)
 - [`hosts.fedora`](#hostsfedora)
 - [`hosts.debian`](#hostsdebian)
@@ -32,6 +33,30 @@ and Unbound, so now it's something I can attempt to `/etc/hosts`.
 
 **_EXCERCISE CAUTION!_**
 
+## `hostname`
+
+As can be seen in `hosts.debian`, Debian specifies hostname in format
+such as:
+
+```
+::1 localhost
+::1 FQDN UQDN
+
+127.0.0.1   localhost
+127.0.1.1   FQDN UQDN
+```
+
+where FQDN means _Fully Qualified Domain Name_ and UQDN _Unqualified Domain
+Name_ (although I don't know if anyone else calls it like that) and I find
+that a good practice. Additionally I have observed my systems querying their
+own hostname from global DNS which seems unnecessary and not a great behaviour
+to me, while this file appended to `/etc/hosts` can tell it immediately all
+applications and make `resolvectl query hostname.localdomain` find it
+instantly.
+
+The `0200:0000:0000:0000:0000:0000:0000:0000`? Replace it with your Yggdrasil
+address from `yggdrasilctl getself`.
+
 ## `hosts.arch`
 
 For now this is a symlink to `hosts.steamos` as I am pretty sure they haven't

etc/hosts/hostname

@@ -0,0 +1,7 @@
+##### BEGIN HOSTNAME #####
+
+::1 fully.qualified.hostname.example.net friendlyhostname
+127.0.1.1 fully.qualified.hostname.example.net friendlyhostname
+#0200:0000:0000:0000:0000:0000:0000:0000 y.friendlyhostname.example.net
+
+##### END HOSTNAME #####