Add GitHub logo as a background to my github repository page

[abhi7187]

[msaimraz]

@abhi7187 Hi can you please assign this issue to me?

[heysubinoy]

Added Changes!

[heysubinoy]

Can you assign me?

[abhi7187]

Can you assign me?

Just add the changes and pull request I will merge it....

[octosapien]

Added the Github logo as background of the webpage .
Added a new CSS file to introduce better and more elaborate styling ( including SVG icons, buttons and flex-display functionalities) into the HTML page .
Also modified the HTML page to improve the overall structuring of elements in the page .

This fixes issue #3 and also adds more functionalities and styles to the page .

Please , accept my Pull Request .