docs: add April 2026 readings and meetup links (#21644)

## Which issue does this PR close?

- Part of #7013

## Rationale for this change

Keep the DataFusion concepts/readings/events page up to date with recent
community content and meetups.

## What changes are included in this PR?

Adds:
- the April 10, 2026 blog post "DataFusion and the Rise of Deconstructed
Data Systems"
- the May 11, 2026 San Francisco Apache DataFusion Meetup discussion and
RSVP link

## Are these changes tested?

Not applicable. This PR only updates markdown documentation links.

## Are there any user-facing changes?

Yes. The documentation page now includes the latest reading and meetup
links.

---------

Co-authored-by: Jeffrey Vo <jeffrey.vo.australia@gmail.com>

Author: alamb

docs/source/user-guide/concepts-readings-events.md

@@ -37,6 +37,8 @@
 
 This is a list of DataFusion related blog posts, articles, and other resources. Please open a PR to add any new resources you create or find
 
+- **2026-04-10** [Blog: DataFusion and the Rise of Deconstructed Data Systems](https://thedataquarry.com/blog/datafusion-and-the-rise-of-deconstructed-data-systems/)
+
 - **2026-04-04** [Video: Generalized Consensus & Native Top-K Joins in ParadeDB](https://www.youtube.com/watch?v=TeFsBVIYBis)
 
 - **2026-03-31** [Blog: Writing Custom Table Providers in Apache DataFusion](https://datafusion.apache.org/blog/2026/03/31/custom-table-providers/)
@@ -202,6 +204,7 @@ This is a list of DataFusion related blog posts, articles, and other resources.
 
 - **2026-07-22** [Denver Apache DataFusion Meetup](https://github.com/apache/datafusion/discussions/18428) - [RSVP](https://luma.com/jsu6faie)
 - **2026-05-12** [New York City Apache DataFusion Meetup](https://github.com/apache/datafusion/discussions/20030) - [RSVP](https://luma.com/adhshv92)
+- **2026-05-11** [San Francisco Apache DataFusion Meetup](https://github.com/apache/datafusion/discussions/21638) - [RSVP](https://luma.com/k3ointcl)
 - **2026-04-23** [Seattle Apache DataFusion Meetup](https://github.com/apache/datafusion/discussions/13500) - [RSVP](https://luma.com/hxshbp0m)
 - **2026-04-22** [Portland Apache DataFusion Meetup](https://github.com/apache/datafusion/discussions/19817) - [RSVP](https://luma.com/dsp3ud82)
 - **2026-03-05** [Stockholm Apache DataFusion Meetup](https://github.com/apache/datafusion/discussions/18429) - [RSVP](https://luma.com/ctqtiqap), [Recording](https://youtu.be/9u4cNmL14Xs)