Document the new galasactl runs delete command

See galasa-dev/projectmanagement#1210

Signed-off-by: James Taylor <[email protected]>

src/data/nav.yaml

@@ -117,6 +117,8 @@
               path: /docs/manage-ecosystem/cli-runs-get
             - title: Downloading test artifacts 
               path: /docs/manage-ecosystem/ecosystem-cli-runs-download
+            - title: Deleting test run results 
+              path: /docs/manage-ecosystem/cli-runs-delete
         - title: Upgrading
           path: /docs/upgrading  
         - title: Managers

src/markdown-pages/docs/manage-ecosystem/runs-delete.md

@@ -0,0 +1,28 @@
+---
+path: "/docs/manage-ecosystem/cli-runs-delete"
+title: "Deleting test run results"
+---
+
+Over time, test run results build up and take up space in the Galasa Ecosystem. You can delete test runs which have completed in the past by using the `galasactl runs delete` command.
+
+You can view the full command syntax in the <a href="https://github.com/galasa-dev/cli/blob/main/docs/generated/galasactl_runs_delete.md" target="_blank">Galasa cli repository</a>.
+
+## Working with the `galasactl runs delete` command
+
+The following example deletes a test run called _C1234_: 
+
+```
+galasactl runs delete --name C1234
+```
+
+## Identifying test runs to delete
+
+Use the `galasactl runs get` command to find the names of the test runs to delete. For example, use the `--age` option to specify a time period in which the tests ran. 
+
+```
+galasactl runs get --bootstrap http://example.com:30960/boostrap --age 6w:1w
+```
+
+The `--format raw` option is useful if you are writing a script to delete multiple test runs.
+
+You can view the full command syntax for `galasactl runs get` in the <a href="https://github.com/galasa-dev/cli/blob/main/docs/generated/galasactl_runs_get.md" target="_blank">Galasa cli repository</a>.