css:added optimized version of the logo

[zygisS22]

i have created 2 versions of the main logo using adobe photoshop to compress size without losing detail.

• logo-trans-optimized size =851kb
• logo-trans-mega-optimized size = 580kb

the original logo size was 1,91mb

here is a GIF to see the difference in image quality

1.Original logo 2. Optimized logo 3. Mega optimized logo

[Akhil-chaudhary]

Your efforts are really appreciated @zygisS22 Thanks for your contribution, do check out other issues of this repo.