docs: What’s new & Upgrade guide 10.3 (#80399)

* initial commit for v10.3 whats new

* Added breaking changes guide and updated What's new doc

* Added 10.2.3 in frontmatter of files

* Added content from What's new in Cloud

* Added note about 10.203 and breaking changes section

* Made formatting edits

* Added 10.2.3 test note

* Replaced 10.2.3 notes with asterisks

* Added tag note

* Move reporting item out of D&V section

* Added breaking changes

* Fixed availability notes

* Moved feature from Traces to Profiles and removed Traces section

* Reordered sections

* Replaced Cloud links with OSS links and relrefs with full URLs

* Updated template

* Copy edit

* Clarified outstanding questions

* Updated data source admin permissions note

* Removed duplicate alerting items

* add InfluxDB SQL support

* Ran prettier

* Added availability, video and contributor info

* Ran prettier

* Added youtube video links

* Removed old video link

---------

Co-authored-by: nmarrs <nathanielmarrs@gmail.com>
Co-authored-by: ismail simsek <ismailsimsek09@gmail.com>

docs/sources/_index.md

@@ -81,8 +81,8 @@ title: Grafana open source documentation
         <h4>Provisioning</h4>
         <p>Learn how to automate your Grafana configuration.</p>
     </a>
-    <a href="{{< relref "whatsnew/whats-new-in-v10-2/" >}}" class="nav-cards__item nav-cards__item--guide">
-        <h4>What's new in v10.2</h4>
+    <a href="{{< relref "whatsnew/whats-new-in-v10-3/" >}}" class="nav-cards__item nav-cards__item--guide">
+        <h4>What's new in v10.3</h4>
         <p>Explore the features and enhancements in the latest release.</p>
     </a>