Fixed typographical error in 'assignment-add.html' and included its appropriate heading

widget_k3git/assignments/templates/assignments/assignment-add.html

 {% extends 'base.html' %}
 
-{% block title %}Add Assigment{% endblock %}
+{% block title %}Add Assignment{% endblock %}
 {% block content %}
+<h1>Add a new assignment:</h1><br>
 <form action="" method="post">
 	{% csrf_token %}
 	{{ form.as_p }}