fixed typo

Author: GbotemiB

index.html

@@ -305,7 +305,7 @@ <h2 class="w3-animate-opacity"><img src="icons/info.png"
 						Research Initiative</a>.
 				</p>
 				<p align='justify'>
-					We are very happy about and constructive feedback and contributions to the <a
+					We are very happy about constructive feedback and contributions to the <a
 						href="https://github.com/PyPSA/" target="_blank" style="color:#004D40">Git-repositories</a>!
 				</p>