Update incremental-microbatch.md

[alexisweill]

What are you changing in this pull request and why?

There is a typo in the example config for microbatch
event_time is updated from session_start to page_view_start

Checklist

• I have reviewed the Content style guide so my content adheres to these guidelines.

[welcome]

Hello!👋 Thanks for contributing to the dbt product documentation and opening this pull request! ✨
We use Markdown and some HTML to write the dbt product documentation. When writing content, you can use our style guide and content types to understand our writing standards and how we organize information in the dbt product docs.
We'll review your contribution and respond as soon as we can. 😄

[vercel]

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[mirnawong1]

hey @alexisweill thanks for opening this pr up! i think session_start is correct bc it tells us when the whole visit to the website began. page_view_start i think focuses on individual page clicks, which isn't helpful when you're trying to understand the entire session.

however, let me confirm internally with the team and I'll get back to you here!

[alexisweill]

@mirnawong1 thanks for checking - I think you are right! it might be worth clarifying in the surrounding text since session_start is only shown in the picture