changedbase.html to templates/base.html

widget_princessgabi/announcementboard/templates/announcementboard/announcement-add.html

-{% extends 'base.html' %}
+{% extends 'templates/base.html' %}
 {% load static %}
 {% block stylesheets %}
 <link rel="stylesheet" type="text/css" href="{% static 'stylesheets/forms.css' %}">

widget_princessgabi/announcementboard/templates/announcementboard/announcement-details.html

-{% extends 'base.html' %}
+{% extends 'templates/base.html' %}
 {% load static %}
 {% block stylesheets %}
 <link rel="stylesheet" type="text/css" href="{% static 'announcementboard/announcements.css' %}">

widget_princessgabi/announcementboard/templates/announcementboard/announcement-edit.html

-{% extends 'base.html' %}
+{% extends 'templates/base.html' %}
 {% load static %}
 {% block stylesheets %}
 <link rel="stylesheet" type="text/css" href="{% static 'stylesheets/forms.css' %}">

widget_princessgabi/announcementboard/templates/announcementboard/announcements.html

-{% extends 'base.html' %}
+{% extends 'templates/base.html' %}
 {% load static %}
 {% block stylesheets %}
 <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">