Added script to make list of headers

Added a new script with the purpose of getting all headers from a post's content and creating links for them in the left sidebar.
Some div classes have been modified, and a wrapper div has been added to posts because of this new script.
Some minor CSS changes have been made.

package.json

@@ -1,7 +1,7 @@
 {
     "name": "mindtheme",
     "description": "Mind Overflow's official website style",
-    "version": "0.0.7",
+    "version": "0.0.8",
     "engines": {
         "ghost-api": "v3"
     },