Update .github/config.yml

Author: reshamas

.github/config.yml

@@ -1,6 +1,6 @@
 # Comment to be posted to on first time issues
 newIssueWelcomeComment: >
-  ![Welcome Banner](https://raw.githubusercontent.com/pymc-devs/brand/main/welcome-bot/BannerWelcome.jpg)]
+  ![Welcome Banner](https://raw.githubusercontent.com/pymc-devs/brand/main/welcome-bot/BannerWelcome.jpg)
 
   :tada: Welcome to _PyMC_! :tada:
   We're really excited to have your input into the project! :sparkling_heart: