Remove generated configurationProperties.adoc from source control

The file is regenerated by generateConfigurationProperties task every build.
Committing it creates unnecessary diff noise.

Assisted-by: Claude Code <Claude@Claude.ai>

Author: jamesfredley

.gitignore

@@ -14,4 +14,5 @@ out
 atlassian-ide-plugin.xml
 plugin-ui/plugin/src/main/templates/views/*
 !etc/bin
-etc/bin/results
+etc/bin/results
+plugin-core/docs/src/docs/configurationProperties.adoc