[SOLVED] ON DEVELOPMENT: PasteMarkdownSyntax. Please, complete it together

Title: PasteMarkdownSyntax.
Required add-ons: Lightning, AdvancedTasks.
Description: This add-on is to paste syntax, as Menu items are: ** Bold, ``` Fence, ### Heading, alt text Image, ----- Horizon and |---- Right-align, |—| Center, ----| Left-align, on dialog description.

Visit the below link for more information and get .xpi file.
Please, support me for completing this add-on.
Please, state your opinion on this forum.
I wish to co-write this add-on. I will do it.

Properties, for example innerHTML, etc., do not respond to target except for value.
What are problems?
What can I do for them?
Please, state your opinion on this forum.

Have a nice day!

Overlay targets are the below:

One of inline scripts in same menu items is the below:

var syntaxArr = new Array;
syntaxArr = [’**’, ‘```’, ‘###’, ‘![alt text]()’, ‘-----’, ‘|----’, ‘|—|’, ‘----|’];
var targetApply = DOMCursor = HTMLInputElement.apply = syntaxArr[7];
window.frames[0].document.activeElement.allowEvents = true;
window.frames[0].document.activeElement.contentEditable = true;
window.frames[0].document.activeElement.__defineGetter__(‘isContentEditable’, function() {return true});
window.frames[0].document.activeElement.value = targetApply;

[SOLVED] with the below script.

Now, PasteMarkdownSyntax 44.0 is available.