Adding logo assets (AcademySoftwareFoundation#235)

Adding here the finalized logo. This is almost identical to the one posted on Slack, except:

  - extremely small adjustment to the arrow head, to make it perfectly centered on and orthogonal to the stroke

  - SVG was optimized to remove redundant elements (e.g. gradients). Main logo is now only 10Kb. PNGs exported at 800dpi.

Author: portsmouth

index.html

@@ -9,12 +9,7 @@
    <a href="https://github.com/AcademySoftwareFoundation/OpenPBR"><img src="images/logo/openpbr-logo-text.svg" alt="homepage" height="100" style="vertical-align: middle; position: relative; bottom: 0px"/></a>
 </center>
 
-<<<<<<< HEAD
-<style>bigger { font-style: italic; font-weight: normal; font-size: 115%;}</style>
-<center><bigger><i>OpenPBR Surface specification v1.1, 2024-06-28</i></bigger></center>
-=======
 <center>*Specification v1.1, 2024-06-28. &nbsp; &nbsp; <a href="https://github.com/AcademySoftwareFoundation/OpenPBR" title="Redirect to GitHub page"><img src="images/aswf-logo-black.svg" alt="homepage" height="18" style="vertical-align: middle; position: relative; bottom: 3px"/></a> *</center>
->>>>>>> b212785 (Merge v1.1 development to main (#222))
 
 <br>
 This document is a specification of a surface shading model intended as a standard for computer graphics: the OpenPBR Surface model. Designed as an über-shader, it aims to be capable of accurately modeling the vast majority of CG materials used in practical visual effects and feature animation productions. The model has been developed as a synthesis of the Autodesk Standard Surface and the Adobe Standard Material models.