Fixed issues with about.html and blog.html

blog.html

* Fixed duplicate class on elements. Each element should only have 1 class="". 
* Fixed nested container classes. 
* Fixed date typo. 
* Adjusted indent spacing. 
* Moved active class in navbar.

about.html

* Fixed duplicate container class. 
* Fixed clas= typo. 
* Moved active class to correct header link.