style: improve CRISPY animation and simplify sidebar footer

- Remove ! from CRISPY, add spacing to smiley
- Use darker green for better contrast
- Increase font size to 1.3rem
- Remove GitHub link from sidebar (keep only Gitea)

src/index.html

@@ -120,8 +120,7 @@
 
 				<footer class="app-footer">
 					<span data-i18n="openSource">Open Source:</span>
-					<a href="https://git.librete.ch/public/code-crispies" target="_blank">Gitea (Source)</a> ·
-					<a href="https://github.com/nextlevelshit/code-crispies" target="_blank">GitHub (Mirror)</a>
+					<a href="https://git.librete.ch/public/code-crispies" target="_blank">Gitea</a>
 					<span data-i18n="by">by</span> <a href="https://librete.ch" title="LibreTECH">LibreTECH</a>
 				</footer>
 			</aside>