ci: add windows support (#7)

Author: v1v

.ci/Jenkinsfile

@@ -55,7 +55,7 @@ pipeline {
         axes {
           axis {
             name 'PLATFORM'
-            values 'macosx && x86_64', 'ubuntu-20.04 && immutable', 'aarch64' // 'windows-2019 && windows-immutable',
+            values 'macosx && x86_64', 'ubuntu-20.04 && immutable', 'aarch64', 'windows-2019 && windows-immutable'
           }
         }
         stages {

README.md

@@ -1,7 +1,4 @@
-[![Build Status](https://beats-ci.elastic.co/job/Beats/job/beats/job/master/badge/icon)](https://beats-ci.elastic.co/job/Beats/job/beats/job/master/)
-[![GoReportCard](http://goreportcard.com/badge/elastic/beats)](http://goreportcard.com/report/elastic/beats)
-[![Reviewed by Hound](https://img.shields.io/badge/Reviewed_by-Hound-8E64B0.svg)](https://houndci.com)
-
+[![Build Status](https://internal-ci.elastic.co/job/elastic-agent/job/elastic-agent-poc-mbp/job/main/badge/icon)](https://internal-ci.elastic.co/job/elastic-agent/job/elastic-agent-poc-mbp/job/main/)
 # POC Elastic Agent
 
 T