Update graph_adjacency_list.py

Author: MaximSmolskiy

graphs/graph_adjacency_list.py

@@ -62,7 +62,6 @@ def add_vertex(self, vertex: T) -> None:
         Adds a vertex to the graph. If the given vertex already exists,
         a ValueError will be thrown.
 
-        Example:
         >>> g = GraphAdjacencyList(vertices=[], edges=[], directed=False)
         >>> g.add_vertex("A")
         >>> g.adj_list