docs: README.md navigation changes for 1.0.0 (apache#12637)

* Made minor adjustments to README navigation, changed some media.

* tweak to subsection title

README.md

@@ -41,7 +41,7 @@ A modern, enterprise-ready business intelligence web application.
 [**Why Superset?**](#why-superset) |
 [**Supported Databases**](#supported-databases) |
 [**Installation and Configuration**](#installation-and-configuration) |
-[**Release Notes**](RELEASING/release-notes-0-38/README.md) |
+[**Release Notes**](RELEASING/README.md#release-notes-for-recent-releases) |
 [**Get Involved**](#get-involved) |
 [**Contributor Guide**](#contributor-guide) |
 [**Resources**](#resources) |
@@ -118,7 +118,7 @@ Here are some of the major database solutions that are supported:
   <img src="superset-frontend/images/oracle.png" alt="oracle" border="0" width="121" height="66" />
   <img src="superset-frontend/images/firebird.png" alt="firebird" border="0" width="86" height="56" />
   <img src="superset-frontend/images/greenplum.png" alt="greenplum" border="0" width="140" height="45" />
-  <img src="superset-frontend/images/clickhouse.png" alt="clickhouse" border="0" width="133" height="34" />  
+  <img src="superset-frontend/images/clickhouse.png" alt="clickhouse" border="0" width="133" height="34" />
   <img src="superset-frontend/images/exasol.png" alt="exasol" border="0" width="106" height="59" />
   <img src="superset-frontend/images/monet-db.png" alt="monet-db" border="0" width="106" height="46" />
   <img src="superset-frontend/images/apache-kylin.png" alt="apache-kylin" border="0" width="56" height="64"/>

RELEASING/README.md

@@ -28,6 +28,10 @@ synchronous communications, we recommend using the `#apache-releases` channel
 on the Superset Slack. People crafting releases and those interested in
 partaking in the process should join the channel.
 
+## Release notes for recent releases
+- [1.0.0](release-notes-1-0/README.md)
+- [0.38](release-notes-0-38/README.md)
+
 ## Release setup (First Time Only)
 
 First you need to setup a few things. This is a one-off and doesn't

RELEASING/release-notes-1-0/README.md

@@ -79,7 +79,9 @@ Charts on dashboards have been updated to concisely show which **filters** are i
 
 **Alerts and reporting** have received a robust backend and UI overhaul.
 
-<kbd><img alt="alerts reports" src="media/alerts_reports.jpg" width="600"/></kbd>
+<kbd><img alt="alerts reports" src="media/alerts_reports_2.jpg" width="600"/></kbd>
+
+<kbd><img alt="alerts reports edit" src="media/alerts_reports_3.jpg" width="600"/></kbd>
 
 See related PR highlights [here](#new-features-1).