I don't know what I did, but it fixed things?!

firefox/index.js

@@ -6,8 +6,10 @@ for (var i = 0; i < sites.length; i++) {
     pattern = Object.keys(sites[i])[0];
     script = sites[i][pattern];
     content_scripts = ["./lib/jquery.js", "./image-lookup.js", "./injections/" + script];
+    console.log('pattern: ' + pattern);
+    console.log('content_scripts: ' + content_scripts);
     pageMod.PageMod({
       include: pattern,
-      contentScriptFile: content_scripts
+      contentScriptFile: content_scripts,
     });
 }

src/image-lookup.js

@@ -1,4 +1,4 @@
 var image_decoder = {
-    "as" : "https://dujrsrsgsd3nh.cloudfront.net/img/emoticons/23362/noot-1438871175.png"
-
+    "form" : "https://dujrsrsgsd3nh.cloudfront.net/img/emoticons/23362/noot-1438871175.png"
 }
+console.log("Image Decoder imported");

src/injections/facebook.js

@@ -34,3 +34,9 @@ $('._55ln').on('click', function() { //Facebook sidebar person is clicked
 $('._552m').on('input paste', function() {  // Text change in textbox. Mainly used to cover all bases
   change_chat_tabs();
 });
+
+
+$(window).on('load', function() {  // When window loads
+  change_chat_tabs();
+});
+alert("Facebook");

src/injections/github.js

@@ -0,0 +1,24 @@
+function change_comments() {
+  $('.comment-body').each(function() {
+    for (var i = 0; i < image_decoder.length; i++) {
+      console.log('Checking for ' + image_decoder[i][0])
+      $(this).html($(this).html().replace(
+        image_decoder[i][0],
+        "<img style='height: 30px; width: 30px;' src='" + image_decoder[i][1] + "'/>"
+      ));
+    }
+  });
+}
+
+$("button.btn[name='comment_and_close']").prev().on('click', function(){  // When the comment button is clicked
+  change_comments();
+});
+
+$('.js-comment-container').on('load change', function(){  // when another comment comes in
+  change_comments();
+});
+
+$(window).on('load', function(){  // When window loads
+  change_comments();
+});
+alert("Github");

src/site-decoder.json

@@ -1,5 +1,6 @@
 {
     "sites": [
-        {"*.facebook.com":"facebook.js"}
+        {"*.facebook.com":"facebook.js"},
+        {"*.github.com":"github.js"}
     ]
 }