Fix broken link to blog post

CONTRIBUTING.md

@@ -18,7 +18,7 @@ and get feedback regarding how to improve its appearance and content.
 Note:
 In case you are just interested to know how to contribute with a
 blog post to _HIFIS Software_ web-page you can find a 
-[blog post]({https://software.hifis.net/tutorials/2019/11/22/How-to-Create-a-new-Blog-Post "How to Create a New Blog Post?")
+[blog post](https://software.hifis.net/tutorials/2019/11/22/How-to-Create-a-new-Blog-Post "How to Create a New Blog Post?")
 explaining the suggested workflow in the blog post section 
 of the web-page.