Blog Post about graduating to a new top level project

[alamb]

Part of #9691

Is your feature request related to a problem or challenge?

Now that DataFusion is its own top level apache project #9691 (comment) we should tell people about it

Describe the solution you'd like

I think we should create one more blog post on https://github.com/apache/arrow-site/ with the announcement and related rationale (from #6475 and Proposal Document) and pointers to our updated docs / links / etc

Describe alternatives you've considered

We could also create a blog post on our own datafusion site (though I am thinking #9602 might be a good first blog post for the DataFusion site)

Additional context

No response

[alamb]

Now that we have completed most of the work on #9691 I hope to draft this post sometime this week

[alamb]

I have created a draft blog post on the arrow site for announcing the new top level project: apache/arrow-site#512

[alamb]

I plan to publish this post tomorrow, May 7 2024

[alamb]

DataFusion Top Level Project announcement is live: https://arrow.apache.org/blog/2024/05/07/datafusion-tlp/