[DOCS] Adds what's new for 8.0 (#123884)

* [DOCS] Adds what's new for 8.0

* [DOCS] Adds info on security

* [DOCS] Fixes broken link

* [DOCS] Copy edit

* Update docs/user/whats-new.asciidoc

Co-authored-by: Adam Locke <adam.locke@elastic.co>

* Update docs/user/whats-new.asciidoc

Co-authored-by: Adam Locke <adam.locke@elastic.co>

* Update docs/user/whats-new.asciidoc

Co-authored-by: Adam Locke <adam.locke@elastic.co>

* [DOCS] Incoporate review comments

* Apply suggestions from code review

Co-authored-by: Kaarina Tungseth <kaarina.tungseth@elastic.co>
Co-authored-by: David Kilfoyle <41695641+kilfoyle@users.noreply.github.com>

* [DOCS] Incorporates review comments

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>
Co-authored-by: Adam Locke <adam.locke@elastic.co>
Co-authored-by: Kaarina Tungseth <kaarina.tungseth@elastic.co>
Co-authored-by: David Kilfoyle <41695641+kilfoyle@users.noreply.github.com>

docs/user/whats-new.asciidoc

@@ -1,8 +1,9 @@
 [[whats-new]]
-== What's new in 8.0
+== What's new in {minor-version}
 
-This section summarizes the most important changes in each release. For the 
-full list, see <<release-notes>> and <<breaking-changes>>. 
+Here are the highlights of what's new and improved in {minor-version}.
+For detailed information about this release,
+check the <<release-notes, release notes>>.
 
 coming[8.0.0]
 
@@ -11,4 +12,85 @@ coming[8.0.0]
 
 // tag::notable-highlights[]
 
+[float]
+=== Security features enabled by default
+
+Authentication, authorization, and multi-tenancy
+with {kib} *Spaces* are on-by-default, with almost no configuration effort.
+When you use {kib} for the first time, you're presented with a new interactive
+UI that helps you securely set up and connect {kib} to {es}.
+Simply paste the enrollment token that you receive when you start
+{es}, and {kib} sets up all the security features
+and connects to {es} over TLS.
+
+[role="screenshot"]
+image::images/highlights-security.png[Configure Elastic to get started]
+
+
+[float]
+[[index-pattern-rename]]
+=== Index patterns are now data views
+Renaming index patterns to data views creates the foundation for building
+new and exciting features in {kib}. Your data views work
+exactly as index patterns did in previous releases.
+
+[float]
+=== Vector tiles and basemap updated
+
+Elastic offers full vector tile support, now generally available, in {kib} *Maps*.
+Enjoy faster performance and smooth navigation of your data at scale.
+
+[role="screenshot"]
+image::images/highlights-maps.png[Three vector tile examples in Maps]
+
+The default basemaps in light and dark themes now use
+the more understated desaturated basemap. This gives your data the most
+visual attention.
+
+[float]
+=== Discover has field statistics (beta)
+
+Enable the new {kibana-ref}/show-field-statistics.html[*Field statistics*] view
+for a summary of all fields (or just selected fields) in your data.
+You'll find interesting fields to visualize and learn more about the shape of your data.
+The *Field statistics* view
+is similar to the *Index Data Visualizer* in *{ml-app}*.
+
+[role="screenshot"]
+image::images/highlights-discover.gif[Fields statistics view in Discover]
+
+[float]
+=== Multi-layered time axis redesigned
+To solve key readability and
+formatting issues, the time axis was upgraded in *Lens*, *TSVB*,
+aggregation-based visualizations, and *Discover*.
+The multi-layered format enables you to create easier to understand visualizations from your data.
+
+[role="screenshot"]
+image::images/highlights-time-axis.gif[Upgraded time axis]
+
+[float]
+=== Heatmaps display data labels
+
+Enable *Show* on labels, and
+when there’s room, a data label appears in each heatmap cell.
+
+[role="screenshot"]
+image::images/highlights-lens.png[Show pop-up on heatmap cell]
+
+[float]
+=== Canvas editing toolbar renovated
+This new design brings a set of editing controls in *Canvas*,
+similar to what you see in *Dashboard*.
+Use the toolbar to quickly access the *Visualization Library* and
+create elements and visualizations.
+
+[role="screenshot"]
+image::images/highlights-canvas.png[Editing toolbar in Canvas]
+
+You can also now
+create embedded visualizations in your *Canvas* workpads.
+Just like in *Dashboard*, you can promote favorites to the *Visualization Library* for re-use.
+
+
 // end::notable-highlights[]