fix: jagged white edge around the logo (#421)

* Fix for the jagged white edge around the logo

This is one way of fixing the issue reported in issue #420, but as mentioned in that issue, this might not be the cleaner, most desirable, way of going about it.

The image is now the same used in allcontributors.org

Fix #420

* Create logo-full.svg

* Replaced external SVG reference to local repo file

* Updated SVG logo with slightly lighter one

Previous one was **6.99k**, new one is **6.69k**, no perceptible quality loss

Author: MicaelJarniac

README.md

@@ -2,7 +2,7 @@
 
 <div align="center">
     <a href="https://allcontributors.org">
-        <img src="docs/assets/logo-full-transparent.png" alt="✨ All Contributors ✨" width="800px" />
+        <img src="docs/assets/logo-full.svg" alt="✨ All Contributors ✨" width="800px" />
     </a>
 </div>