Add extra requirement in new icon pr template (#642)

* Add extra requirement in new icon pr template

* Update .github/PULL_REQUEST_TEMPLATE/new_icon.md

Co-authored-by: Clemens Bastian <8781699+amacado@users.noreply.github.com>

Co-authored-by: Clemens Bastian <8781699+amacado@users.noreply.github.com>

Author: Thomas-Boi

.github/PULL_REQUEST_TEMPLATE/new_icon.md

@@ -7,3 +7,8 @@
 - [] A new object is added in the `devicon.json` file as seen [here](https://github.com/devicons/devicon/blob/develop/CONTRIBUTING.md#-updating-the-deviconjson-)
 
 Refer to the [`CONTRIBUTING.md`](https://github.com/devicons/devicon/blob/develop/CONTRIBUTING.md#contributing-to-devicon) for more details.
+
+
+**Link to official page to prove your SVG is correct and update to date**
+
+*Link goes here*