Updates to OpenPGP best practices

When translating into spanish i noticed some issues with the OpenPGP Best Practices document. This will remove a wrong link in the document, fix some incosistences as GnuPG is an implementation for OpenPGP and it also will fix some typos. 
The link is a wrong link... if you try to verify the CA Cert with the data you find there it will fail as it's just to verifty the https server of https://sks-keyservers.net. 

The correct link it's https://sks-keyservers.net/overview-of-pools.php, at the bottom there is the OpenPGP signature of this file. So, to veritfy it you need to import Kristian Fiskerstrand's key, which you can get using the full Key ID noted there. There are two problems with doing this:

This document explicit that you should not use the full KeyID but the fingerprint of the person you are trying to reach. 

When i import it and try to use i don't have a trust path which is something common, since i don't have a trust path for more of the keys. ... but i expected to see that somebody from the riseup collective signed this key so i don't have to be totally blindly trusting it. 

This means i'm not able to really veritfy this CA Cert file. Ok this can be just me, and maybe most of the people have a trust path to Kristian Fiskerstrand's OpenPGP key... but i can't assume that so i just made the change to remove the bad link. It's up to you if it's ok tell to people trust that key (in which case you can sign that one as a collective or something).

Note: i found some key signing the Fiskerstrand's key with a @debian.org identity, but it was not in the Debian keyrign.

guido@kaosu:~$ gpg --keyring=/usr/share/keyrings/debian-keyring.gpg --list-key 0x387706a26998e5c4
gpg: error reading key: Clave pública no encontrada