Add security releases to the patch calendar (magento#7003)

* Adjusted patch releases

* Update src/release/index.md

Co-Authored-By: Dmitry Shevtsov <[email protected]>

Co-authored-by: Donald Booth <[email protected]>
Co-authored-by: Dmitry Shevtsov <[email protected]>

Author: 3 people

src/release/index.md

@@ -21,14 +21,20 @@ The following table describes the status of Magento software availability and wh
 
 ## Patch schedule
 
-Magento releases security and functional patches for each supported release line of {{site.data.var.ee}} every quarter. The following table provides the dates for each patch scheduled for release in 2020.
-
-| Version | Pre-release | GA         |
-|---------|-------------|------------|
-| 2.3.4   | January 14  | January 28 |
-| 2.3.5   | April 14    | April 28   |
-| 2.3.6   | July 14     | July 28    |
-| 2.3.7   | October 1   | October 15 |
+Magento releases security and functional patches for each supported release line of {{site.data.var.ee}} every quarter.
+
+Security releases provide fixes for vulnerabilities that have been identified in previous quarterly patch releases. You can install time-sensitive security fixes without applying the hundreds of functional fixes and enhancements that a full quarterly patch release contains. These releases are appended with `-p1`.
+
+For general information about security releases, see [Introducing the New Security-only Patch Release](https://community.magento.com/t5/Magento-DevBlog/Introducing-the-New-Security-only-Patch-Release/ba-p/141287). For instructions on downloading and applying security patches, see [Install Magento using Composer]({{site.baseurl}}/guides/v2.3/install-gde/composer.html).
+
+The following table provides the dates for each patch scheduled for release in 2020:
+
+| Version           | Pre-release | GA         |
+|-------------------|-------------|------------|
+| 2.3.4<br>2.3.3-p1 | January 14  | January 28 |
+| 2.3.5<br>2.3.4-p1 | April 14    | April 28   |
+| 2.3.5-p1          | July 14     | July 28    |
+| 2.3.6             | October 1   | October 15 |
 
 _These dates are subject to change._