Merge infra and k3 into one directory again

Since I don't have multiple terraform steps anymore it simply doesn't
make sense to me anymore to split all tasks into separate folders.
Instead I try to be as clear as possible in the README to make it easy
to follow the structure in the future without too much headache.

roles/server-setup/handlers/main.yml

@@ -0,0 +1,7 @@
+- name: Restart sshd
+  service:
+    name: ssh
+    state: restarted
+
+- name: Start ip-masquerade
+  script: "{{ ip_masquerade_path }}/{{ ip_masquerade_script }}"