config: proper pipeline configuration to allow main builds as well as PR triggers (#2769)

* add a comment about the pipeline

* fix config to support builds on PRs

Author: delanni

README.md

@@ -53,6 +53,9 @@ yarn start
 We use [storybook](https://storybook.js.org) to document API, edge-cases, and the usage of the library.
 A hosted version is available at [https://elastic.github.io/elastic-charts/storybook][docs].
 
+## CI
+We're using the same [build pipeline](https://buildkite.com/elastic/kibana-elastic-charts-build) for building PRs and the main branch. This pipeline is triggered through webhook events hitting the [buildkite-pr-bot](https://github.com/elastic/buildkite-pr-bot). Configuration for the triggered pipelines can be adjusted in [pull-requests.json](./.buildkite/pull-requests.json).
+
 ## Goals
 
 The primary goal of this library is to provide reusable set of chart components that can be used throughout Elastic's web products.

catalog-info.yaml

@@ -23,6 +23,12 @@ spec:
       repository: elastic/elastic-charts
       provider_settings:
         trigger_mode: none
+        build_branches: true
+        build_pull_requests: true
+        build_tags: false
+        prefix_pull_request_fork_branch_names: false
+        skip_pull_request_builds_for_existing_commits: false
+      branch_configuration: 'main'
       pipeline_file: ".buildkite/pipelines/pull_request/pipeline.sh"
       teams:
         kibana-visualizations: