Convert configuration to use |to_json

roles/matrix-bot-matrix-registration-bot/templates/config/config.yml.j2

@@ -1,12 +1,12 @@
 bot:
-  server: "{{ matrix_bot_matrix_registration_bot_bot_server }}"
-  username: "{{ matrix_bot_matrix_registration_bot_matrix_user_id_localpart }}"
-  access_token: "{{ matrix_bot_matrix_registration_bot_bot_access_token }}"
+  server: {{ matrix_bot_matrix_registration_bot_bot_server|to_json }}
+  username: {{ matrix_bot_matrix_registration_bot_matrix_user_id_localpart|to_json }}
+  access_token: {{ matrix_bot_matrix_registration_bot_bot_access_token|to_json }}
 api:
   # API endpoint of the registration tokens
-  base_url: '{{ matrix_bot_matrix_registration_bot_api_base_url }}'
+  base_url: {{ matrix_bot_matrix_registration_bot_api_base_url|to_json }}
   # Access token of an administrator on the server
-  token: "{{ matrix_bot_matrix_registration_bot_api_token }}"
+  token: {{ matrix_bot_matrix_registration_bot_api_token|to_json }}
 logging:
-  level: "{{ matrix_bot_matrix_registration_bot_logging_level }}"
+  level: {{ matrix_bot_matrix_registration_bot_logging_level|to_json }}