More tutorial placeholders

docs/backup-restore.md

@@ -0,0 +1,5 @@
+---
+title: Back-up and restore an application
+---
+
+TODO.

docs/git.md

@@ -0,0 +1,5 @@
+---
+title: Use git to manage your configuration
+---
+
+TODO.

docs/hardening.md

@@ -0,0 +1,5 @@
+---
+title: Consider Docker security hardening practices
+---
+
+TODO.

docs/rollback.md

@@ -0,0 +1,5 @@
+---
+title: Roll an application back to a previous version
+---
+
+TODO.

docs/scale.md

@@ -0,0 +1,5 @@
+---
+title: Scale an application up to handle more traffic
+---
+
+TODO.

docs/secrets.md

@@ -0,0 +1,5 @@
+---
+title: Manually load secrets into Docker swarm
+---
+
+TODO.