Add 1.9.0 to downloads page

Signed-off-by: Kai Hudalla <[email protected]>

site/documentation/tag_stable.txt

@@ -1 +1 @@
-1.9.0
+1.9.x

site/documentation/versions_supported.csv

@@ -9,4 +9,4 @@ MAJOR;MINOR;BRANCH_OR_TAG
 1;6;1.6.x
 1;7;1.7.x
 1;8;1.8.x
-1;9;1.9.0
+1;9;1.9.x

site/homepage/content/downloads.md

@@ -21,7 +21,7 @@ for installation instructions.
 
 A Java based command line client for consuming telemetry data and events from Hono is available for download from
 
-* [Eclipse Hono 1.8.1 Command Line Client](https://www.eclipse.org/downloads/download.php?file=/hono/hono-cli-1.8.1-exec.jar)
+* [Eclipse Hono 1.9.0 Command Line Client](https://www.eclipse.org/downloads/download.php?file=/hono/hono-cli-1.9.0-exec.jar)
 
 The client requires a Java 11 runtime environment to run.
 
@@ -39,9 +39,5 @@ For a list of the changes in this release, take a look at the [release notes]({{
 
 ## Previous versions
 
+* [Eclipse Hono 1.8.1 Command Line Client](https://www.eclipse.org/downloads/download.php?file=/hono/hono-cli-1.8.1-exec.jar)
 * [Eclipse Hono 1.8.0 Command Line Client](https://www.eclipse.org/downloads/download.php?file=/hono/hono-cli-1.8.0-exec.jar)
-* [Eclipse Hono 1.7.4 Command Line Client](https://www.eclipse.org/downloads/download.php?file=/hono/hono-cli-1.7.4-exec.jar)
-* [Eclipse Hono 1.7.3 Command Line Client](https://www.eclipse.org/downloads/download.php?file=/hono/hono-cli-1.7.3-exec.jar)
-* [Eclipse Hono 1.7.2 Command Line Client](https://www.eclipse.org/downloads/download.php?file=/hono/hono-cli-1.7.2-exec.jar)
-* [Eclipse Hono 1.7.1 Command Line Client](https://www.eclipse.org/downloads/download.php?file=/hono/hono-cli-1.7.1-exec.jar)
-* [Eclipse Hono 1.7.0 Command Line Client](https://www.eclipse.org/downloads/download.php?file=/hono/hono-cli-1.7.0-exec.jar)