Mount local users .ssh directory into the dev container in order to use SSH keys for signing off git commits

Signed-off-by: Adam Warner <me@adamwarner.co.uk>

.devcontainer/devcontainer.json

@@ -7,5 +7,9 @@
     "ms-vscode.cpptools",
     "ms-vscode.cmake-tools",
     "eamodio.gitlens"
+  ],
+  "mounts": [
+    "type=bind,source=/home/${localEnv:USER}/.ssh,target=/root/.ssh,readonly"
   ]
+
 }