corrected ansible errors

README.md

@@ -38,12 +38,12 @@ yunohost:
       pass: p@ssw0rd
       firstname: Jane
       lastname: Doe
-      domain: {{ domain }} 
+      domain: '{{ domain }}'
     - name: user2 # user which uses the first extra_domain for its account
       pass: p@ssw0rd
       firstname: John 
       lastname: Doe
-      domain: {{ extra_domain.[1] }} 
+      domain: '{{ extra_domain.[1] }}'
   admin_users: 
     - name: admin # user generated by yunohost as its admin user  
       key: ssh-rsa ... # key for admin user 

tasks/admin_users.yml

@@ -1,5 +1,5 @@
 ---
-- name: add sshkey for admin user:
+- name: add sshkey for admin user
   ansible.posix.authorized_key:
     user: "{{ item.name }}"
     state: present