Docs: What’s new & Upgrade guide & Breaking changes v11.0-preview (#84603)

* Updated index pages and added 11.0 breaking changes, upgrade guide, and what's new pages

* Removed references to 10.4

* Added draft breaking changes

* docs: grafana11-upgrade: postgres (#84671)

* docs: grafana11-upgrade: postgres

* fix typos

Co-authored-by: Sriram <153843+yesoreyeram@users.noreply.github.com>

* improved text

Co-authored-by: Isabel Matwawana <76437239+imatwawana@users.noreply.github.com>

* improved text

Co-authored-by: Isabel Matwawana <76437239+imatwawana@users.noreply.github.com>

* improved text

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Co-authored-by: Sriram <153843+yesoreyeram@users.noreply.github.com>
Co-authored-by: Isabel Matwawana <76437239+imatwawana@users.noreply.github.com>

* Added internal note

* Added what's new items

* Added more breaking changes'

* Copy edits

* Revert "docs: grafana11-upgrade: postgres" (#85580)

Revert "docs: grafana11-upgrade: postgres (#84671)"

This reverts commit d766d734c2.

* Removed internal link and moved PR link

* Added new entries

* Made fixes

* Updated name

* Copy edits

* Fixed links and minor copy edits

* Removed link to Cloud What's new

* Added OSS what's new link

* Fixed spelling of GitHub

* Added Explore Logs and updated Explore Metrics

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Co-authored-by: Gábor Farkas <gabor.farkas@gmail.com>
Co-authored-by: Sriram <153843+yesoreyeram@users.noreply.github.com>

docs/sources/upgrade-guide/upgrade-v11.0/index.md

@@ -0,0 +1,23 @@
+---
+description: Guide for upgrading to Grafana v11.0-preview
+keywords:
+  - grafana
+  - configuration
+  - documentation
+  - upgrade
+  - '11.0'
+  - '11.0-preview'
+title: Upgrade to Grafana v11.0-preview
+menuTitle: Upgrade to v11.0
+weight: 1200
+---
+
+# Upgrade to Grafana v11.0-preview
+
+{{< 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