fix(crawler-gradle): MXTS-74974: add com.maxxton.microdocs.crawler plugin descriptor

The version-catalog alias (libs.plugins.microdocs -> id
com.maxxton.microdocs.crawler) resolves the plugin via the plugins{} DSL.
That path needs the impl jar to carry META-INF/gradle-plugins/
com.maxxton.microdocs.crawler.properties, matching the Gradle Plugin
Portal marker. The jar only shipped the legacy microdocs.properties
(id 'microdocs'), so apply failed with 'does not provide a plugin with
id com.maxxton.microdocs.crawler'. Keep both descriptors for backward
compat with apply plugin: 'microdocs' consumers.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: mxt-mischa

microdocs-crawler-gradle/src/main/resources/META-INF/gradle-plugins/com.maxxton.microdocs.crawler.properties

@@ -0,0 +1 @@
+implementation-class=com.maxxton.microdocs.crawler.gradle.MicroDocsCrawlerPlugin