$('document').ready(function() {
	require(['composer', 'composer/controls'], function(composer, controls) {
		composer.addButton('fa fa-code', function(textarea, selectionStart, selectionEnd) {
			if(selectionStart === selectionEnd){
				controls.insertIntoTextarea(textarea, '```\nInsert Code Here\n```');
				controls.updateTextareaSelection(textarea, selectionStart + 4);
			} else {
				controls.wrapSelectionInTextareaWith(textarea, '```\n','\n```');
				controls.updateTextareaSelection(textarea, selectionStart + 4, selectionEnd);
			}
		});
		composer.addButton('fa fa-strikethrough', function(textarea, selectionStart, selectionEnd) {
			if(selectionStart === selectionEnd){
				controls.insertIntoTextarea(textarea, '~~Insert Text Here~~');
				controls.updateTextareaSelection(textarea, selectionStart + 2);
			} else {
				controls.wrapSelectionInTextareaWith(textarea, '~~','~~');
				controls.updateTextareaSelection(textarea, selectionStart + 2, selectionEnd);
			}
		});
	});
});

@@ -365,16 +365,35 @@
 tart + 4
+, selectionEnd + 21
 );%0A%09%09%09%7D 
@@ -460,24 +460,26 @@
 %60%60%5Cn','%5Cn%60%60%60
+%5Cn
 ');%0A%09%09%09%09cont
@@ -541,32 +541,36 @@
  4, selectionEnd
+ + 4
 );%0A%09%09%09%7D%0A%09%09%7D);%0A%09%09
@@ -834,16 +834,35 @@
 tart + 2
+, selectionEnd + 18
 );%0A%09%09%09%7D 
@@ -1010,16 +1010,20 @@
 ctionEnd
+ + 2
 );%0A%09%09%09%7D%0A

Update buttons.js