feat: Updating yubikey notes.

Yubikey.md

@@ -2,6 +2,44 @@
 
 A list of sites that my yubikey's are registerd with.
 
-| Site | Primary Key Registered | Backup Key Registered |
-| ---- | :--------------------: | :-------------------: |
-| Test |           ✅           |                       |
+| Site        | Primary Key Registered | Backup Key Registered |
+| ----------- | :--------------------: | :-------------------: |
+| Proton      |           ✅           |                       |
+| Facebook    |           ✅           |                       |
+| M4-Mac-Mini |           ✅           |                       |
+| github      |           ✅           |                       |
+| gitea       |           ✅           |                       |
+
+## Moving GPG keys onto Yubikey
+
+[helpful-youtube-video](https://www.youtube.com/watch?v=xGsixSh6sC4)
+
+The `GPG-Suite` application needs to be installed on macOS in order to interact with the yubikey.
+This then gives you access to use the `gpg --card-edit` command that allows you to add gpg-keys to
+the yubikey itself.
+
+### Default PIN's for yubikey (need changed below).
+
+1. User: 123456
+1. Admin: 12345678
+
+### Sequence (from memory, may be off / need checked).
+
+1. `gpg --card-edit`
+1. `admin`
+
+## Setting up macOS to use gpg-agent for ssh
+
+The following lines need added to `~/.gnupg/gpg-agent.conf`, `enable-ssh-support`.
+
+```bash
+echo enable-ssh-support > ~/.gnupg/gpg-agent.conf
+```
+
+The following lines were added to `.zshrc` to enable the usage of the gpg-agent for ssh (should need
+to be done again, as long as dotfiles are installed and linked correctly).
+
+```bash
+gpgconf --launch gpg-agent
+export SSH_AUTH_SOCK=~/.gnupg/S.gpg-agent.ssh
+```