Vertex controlling scripts are in 0_Scripts/Editable
Before use them, you need Editable tag and layer in Unity editor.

EditableThing
└─ EditableVertex
└─ EditableLine
EditableObject
IUpdatable

EditableThing is abstract parent of EditableVertex, EditableLine
EditableVertex and EditableLine actually represent controllable elements.
EditableObject is object that contains editable vertices and lines.
And through IUpdatable, rendering information is updated.

You don't need to create EditableVertex and EditableLine your own.
Just put EditableObject script to whatever you want control.
After that, call Init() of EditableObject. Thats all.

private void Awake(){
    EditableObject eObject = addComponent<EditableObject>();
    eObject.Init();
}