bug#47971: Improve Guix commands for update/upgrade

[bo0od]

Hi There,

The current commands used to make sure everything updated are not 
friendly to type nor to memorize, Current commands:(i dunno if i missed 
more)

guix pull
guix upgrade
sudo guix reconfigure /etc/config.scm


There is no relation can be drawn from using these commands:

- pull: Is actually the opposite of push which is a git command and it 
make sense in git atmosphere/usage.

- upgrade: This is the only good one as this is very common term used 
within distros or actually most of the operating systems generally.

- reconfigure /etc/config.scm: hmm...

There are many ways we can improve this by using different better terms 
which can be easily memorized and even linked e.g: (These are just 
examples, If there are any better terms you can come with sure why not)

- pull -> update or refresh
- upgrade -> can be kept or package-upgrade
- reconfigure /etc/config.scm -> dist-upgrade or distro-upgrade or 
system-upgrade

----

OR There is another approach some distros taking which is using 
shortcuts to only letters e.g

pull -> p or -p
upgrade -> u or -u
reconfigure -> re or -re

as a one world for memory "pure" (any other letters can be used as well)

ThX!