Docs: SigV4 What's New and AWS Elasticsearch documentation (#28506)

* add what's new entry and elastic docs

* update docs

* remove caps

* fix image path

* fix md link

Co-authored-by: Sofia Papagiannaki <papagian@users.noreply.github.com>

* fix link case

Co-authored-by: Sofia Papagiannaki <papagian@users.noreply.github.com>

* fix md link

* docs fixes

* update config ref

Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>

Co-authored-by: Sofia Papagiannaki <papagian@users.noreply.github.com>
Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>

docs/sources/datasources/elasticsearch.md

@@ -248,3 +248,19 @@ datasources:
       logMessageField: message
       logLevelField: fields.level
 ```
+
+## Amazon Elasticsearch Service
+
+AWS users using Amazon's Elasticsearch Service can use Grafana's Elasticsearch data source to visualize Elasticsearch data.
+If you are using an AWS Identity and Access Management (IAM) policy to control access to your Amazon Elasticsearch Service domain, then you must use AWS Signature Version 4 (AWS SigV4) to sign all requests to that domain.
+For more details on AWS SigV4, refer to the [AWS documentation](https://docs.aws.amazon.com/general/latest/gr/signature-version-4.html).
+
+### AWS Signature Version 4 authentication
+
+> **Note:** Only available in Grafana v7.3+.
+
+In order to sign requests to your Amazon Elasticsearch Service domain, SigV4 can be enabled in the Grafana [configuration]({{< relref "../administration/configuration.md#sigv4_auth_enabled" >}}).
+
+Once AWS SigV4 is enabled, it can be configured on the Elasticsearch data source configuration page. Refer to [Cloudwatch authentication]({{<relref "./cloudwatch.md#authentication" >}}) for more information about authentication options.
+
+{{< docs-imagebox img="/img/docs/v73/elasticsearch-sigv4-config-editor.png" max-width="500px" class="docs-image--no-shadow" caption="SigV4 configuration for AWS Elasticsearch Service" >}}

docs/sources/whatsnew/whats-new-in-v7-3.md

@@ -15,14 +15,13 @@ weight = -17
 
 This topic includes the release notes for Grafana v7.3. For all details, read the full [CHANGELOG.md](https://github.com/grafana/grafana/blob/master/CHANGELOG.md).
 
-## Highlights
-
-Grafana 7.3 comes with a number of features and enhancements:
+The main highlights are:
 
 - [**Google Cloud Monitoring:** Out of the box dashboards]({{< relref "#cloud-monitoring-out-of-the-box-dashboards" >}})
 - [**Shorten URL for dashboards and Explore**]({{< relref "#shorten-url-for-dashboards-and-explore" >}})
 - [**Table improvements and new image cell mode**]({{< relref "#table-improvements-and-new-image-cell-mode" >}})
 - [**New color scheme option**]({{< relref "#new-color-scheme-option" >}})
+- [**SigV4 Authentication for Amazon Elasticsearch Service**]({{< relref "#sigv4-authentication-for-aws-users" >}})
 
 ## Table improvements and new image cell mode
 
@@ -61,9 +60,9 @@ As this new option is a standard field option it works in every panel. Here is a
 {{< figure src="/img/docs/v73/bar_gauge_gradient_color_scheme.png" max-width="900px" caption="bar gauge color scheme" >}}
 
 
-#### Cloud monitoring out-of-the-box dashboards
+## Google Cloud monitoring out-of-the-box dashboards
 
-The updated Cloud monitoring data source is shipped with pre-configured dashboards for five of the most popular GCP services:
+The updated Google Cloud monitoring data source is shipped with pre-configured dashboards for five of the most popular Google Cloud Platform (GCP) services:
 
 - BigQuery
 - Cloud Load Balancing
@@ -77,7 +76,13 @@ For more details, see the [Google Cloud Monitoring docs]({{<relref "../datasourc
 
 ## Shorten URL for dashboards and Explore
 
-This is an amazing new feature that was created in cooperation with one of our community members. The new **share shortened link** capability allows you to create smaller and simpler URLs of the format `/goto/:uid` instead of using longer URLs that can contain complex query parameters. In Explore, you can create a shortened link by clicking on the share button in Explore toolbar. In the dashboards, a shortened url option is available through the share panel or dashboard button.
+This is an amazing new feature that was created in cooperation with one of our community members. The new share shortened link capability allows you to create smaller and simpler URLs of the format `/goto/:uid` instead of using longer URLs that can contain complex query parameters. In Explore, you can create a shortened link by clicking on the share button in Explore toolbar. In the dashboards, a shortened url option is available through the share panel or dashboard button.
+
+## SigV4 authentication for AWS users
+
+You can now configure your Elasticsearch data source to access your Amazon Elasticsearch Service domain directly from Grafana.
+
+For more details, refer to the [Elasticsearch docs]({{<relref "../datasources/elasticsearch/#aws-signature-version-4-authentication">}}).
 
 ## Grafana Enterprise features