enhance scrape config (#913)

* enhance scrape config:
1. add ScrapeConfig CRD
address #847, #803
2. add `series_limit` option in scrape_configs, see https://docs.victoriametrics.com/vmagent/#scrape_config-enhancements.
3. add proxyUrl for VMProbe, address #731
4. fix option `disable_keep_alive` -> `disable_keepalive`
5. deprecate option `relabel_debug` and  `metric_relabel_debug` in scrape_configs, they were deprecated since [v1.85.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v1.85.0).

* fix test

* fix

* add docs

* add changelog

* add test

* typo

* simplify convert code

README.md

@@ -12,11 +12,12 @@
 ## Overview
 
  Design and implementation inspired by [prometheus-operator](https://github.com/prometheus-operator/prometheus-operator). It's great a tool for managing monitoring configuration of your applications. VictoriaMetrics operator has api capability with it.
-So you can use familiar CRD objects: `ServiceMonitor`, `PodMonitor`, `PrometheusRule` and `Probe`. Or you can use VictoriaMetrics CRDs:
+So you can use familiar CRD objects: `ServiceMonitor`, `PodMonitor`, `PrometheusRule`, `Probe` and `ScrapeConfig`. Or you can use VictoriaMetrics CRDs:
 - `VMServiceScrape` - defines scraping metrics configuration from pods backed by services.
 - `VMPodScrape` - defines scraping metrics configuration from pods.
 - `VMRule` - defines alerting or recording rules.
 - `VMProbe` - defines a probing configuration for targets with blackbox exporter.
+- `VMScrapeConfig` - define a scrape config using any of the service discovery options supported in victoriametrics.
 
 Besides, operator allows you to manage VictoriaMetrics applications inside kubernetes cluster and simplifies this process [quick-start](/docs/quick-start.md)
 With CRD (Custom Resource Definition) you can define application configuration and apply it to your cluster [crd-objects](/docs/api.md).