New output plugin: logstash-output-azuresearch

I would like to contribute a new logstash output plugin, logstash-output-azuresearch. The plugin can be found here:
https://github.com/yokawasa/logstash-output-azuresearch

The plugin makes possible to store logs in Azure Search, a managed cloud search service provided in Microsoft Azure. Please add the plugin to the logstash-plugins project if you find it useful

Start by reviewing the linked logstash-output-azuresearch repository and comparing it with the logstash-plugins project. Determine the project’s acceptance requirements for a new Azure Search output plugin; done means the plugin is integrated into logstash-plugins and its behavior is accepted by maintainers.

Written by the indexing model from the issue text.