Rename exercises dir

Name it instead "topics" so it won't be
strange if some topics included "exercises" directory.

topics/containers/solutions/containerized_db_persistent_storage.md

@@ -0,0 +1,24 @@
+# Containerized DB with Persistent Storage
+
+1. Run a container with a database of any type of you prefer (MySql, PostgreSQL, Mongo, etc.)
+  1. Use a mount point on the host for the database instead of using the container storage for that
+  2. Explain why using the host storage instead of the container one might be a better choice
+2. Verify the container is running
+
+
+## Solution
+
+```
+# Create the directory for the DB on host
+mkdir -pv ~/local/mysql
+sudo semanage fcontext -a -t container_file_t '/home/USERNAME/local/mysql(/.*)?'
+sudo restorecon -R /home/USERNAME/local/mysql
+
+# Run the container
+podman run --name mysql -e MYSQL_USER=mario -e MYSQL_PASSWORD=tooManyMushrooms -e MYSQL_DATABASE=university -e MYSQL_ROOT_PASSWORD=MushroomsPizza -d mysql -v /home/USERNAME/local/mysql:/var/lib/mysql/db
+
+# Verify it's running
+podman ps
+```
+
+It's better to use the storage host because in case the container ever gets removed (or storage reclaimed) you have the DB data still available.