add ssh-keygen

builds up to options

Updates verbiage

pages/common/ssh-keygen.md

@@ -0,0 +1,19 @@
+# ssh-keygen
+
+> Generate ssh keys user for authentication, password-less logins, and other things
+
+- generate a key interactively
+
+`ssh-keygen`
+
+- generate a DSA 2048 bit (default) key
+
+`ssh-keygen -t dsa`
+
+- generate an RSA 4096 bit key with your email as a comment
+
+`ssh-keygen -t rsa -b 4096 -C "{{email}}"`
+
+- Retrieve the key fingerprint from a host (useful for confirming the authenticity of the host when first connecting to it via SSH)
+
+`ssh-keygen -l -F {{remote_host}}`