Hello world link in pr welcome text broken

[patmmccann]

          > Hi @tongwu-sh ? It seems your adapter needs a tiny bit of additional maintenance: please move the common get connection logic in your adapter and prisma into a file in /libraries

It seems you also have a bug in your battr support; I think it is on imp.banner instead of imp

Please also document this endpoint change on the docs repo

Thanks for the comments; I've made the updates. How should we test this part? Be sure to test the integration with your ad server using the [Hello World](https://github.com/integrationExamples/gpt/hello_world.html) sample page. It seems the URL is not working.

Originally posted by @tongwu-sh in #12004 (comment)