Rename exercises dir

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

topics/aws/exercises/register_domain/solution.md

@@ -0,0 +1,27 @@
+## AWS Route 53 - Register Domain
+
+### Objectives
+
+Note: registering domain costs money. Don't do this exercise, unless you understand that you are going to register a domain and it's going to cost you money.
+
+1. Register your own custom domain using AWS Route 53
+2. What is the type of your domain?
+3. How many records your domain has?
+
+### Solution
+
+1. Go to Route 53 service page
+2. Click in the menu on "Registered Domains" under "Domains"
+3. Click on "Register Domain"
+4. Insert your domain
+5. Check if it's available. If it is, add it to the cart 
+
+Note: registering domain costs money. Don't click on "continue", unless you understand that you are going to register a domain and it's going to cost you money.
+
+6. Click on "Continue" and fill in your contact information
+7. Choose if you want to renew it in the future automatically. Accept the terms and click on "Complete Order"
+8. Go to hosted zones and you should see there your newly registered domain
+
+1. The domain type is "Public"
+
+1. The domain has 2 DNS records: NS and SOA