[Feature Request] Add the ability to destruct the editor

If there is a place where we are conditionally showing the editor, then it is better to have a destruct method.

var simplemde = new SimpleMDE({ element: document.getElementById("MyID") });

And when there is a need to hide/remove the editor:

simplemde.destruct();

It should remove all the elements that were added because of the construct method.

[Ionaru]

It is mentioned in the readme. https://github.com/Ionaru/easy-markdown-editor#removing-easymde-from-text-area

[Ionaru]

Renaming the toTextArea() function is not possible in any 2.x.x version because it would break backwards compatibility. Maybe an alias is acceptable?