Clarify what permissions is actually needed for Azure Devops PAT

[hauskens]

In this segment: https://docs.coderabbit.ai/platforms/azure-devops/#generating-a-personal-access-token

The screenshot shows these permissions:
Work items - Read, write & manage
Code - Read - write & manage
Build - Read

But in the text, it states:
'We need to have read & write access to "Work Items" & "Code" to post reviews on pull requests. If you are on the Pro tier also add "Build" access for pipeline failure remediation.'