improve yubikey ssh instructions

content/blog/yubikey-ssh.md

@@ -41,7 +41,7 @@ You can even PIN protect the key, which means that if somebody physically steals
 
 ## Set Yubikey PINs
 
-Install `gpg` using your operating system's package manager so that you can interact with your Yubikey.
+**Install `gpg` using your operating system's package manager** so that you can interact with your Yubikey.
 
 > `gpg 2.2.23` has a bug that prevents on-card key generation. Despite what's written in the bug report, we've had success with version `2.2.22`.
 
@@ -118,6 +118,8 @@ echo "pinentry-program /usr/local/bin/pinentry-mac" >> ~/.gnupg/gpg-agent.conf
 
 <img src="/img/blog/pinentry-mac.png" class="image fit">
 
+**You _may_ need to restart your machine for all changes to take effect.**
+
 ## Generate an RSA key on your Yubikey
 
 I recommend [generating your RSA key on the Yubikey itself](#roca), rather than generating the key on your computer and then copying it to the Yubikey. This way you know that it has never been on the filesystem, where it could be snooped upon.