Update cheatsheets

ssh-agent

@@ -0,0 +1,19 @@
+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# ssh-agent
+
+> Spawn an SSH Agent process.
+> An SSH Agent holds SSH keys decrypted in memory until removed or the process is killed.
+> See also `ssh-add`, which can add and manage keys held by an SSH Agent.
+> More information: <https://man.openbsd.org/ssh-agent>.
+
+- Start an SSH Agent for the current shell:
+
+`eval $(ssh-agent)`
+
+- Kill the currently running agent:
+
+`ssh-agent -k`