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/upgrade-guide/upgrade-v10.3/index.md

@@ -0,0 +1,23 @@
+---
+description: Guide for upgrading to Grafana v10.3
+keywords:
+  - grafana
+  - configuration
+  - documentation
+  - upgrade
+  - '10.3'
+  - '10.2.3'
+title: Upgrade to Grafana v10.3
+menuTitle: Upgrade to v10.3
+weight: 1400
+---
+
+# Upgrade to Grafana v10.3
+
+{{< docs/shared lookup="upgrade/intro.md" source="grafana" version="<GRAFANA VERSION>" >}}
+
+{{< docs/shared lookup="back-up/back-up-grafana.md" source="grafana" version="<GRAFANA VERSION>" leveloffset="+1" >}}
+
+{{< docs/shared lookup="upgrade/upgrade-common-tasks.md" source="grafana" version="<GRAFANA VERSION>" >}}
+
+## Technical notes