Support add annotations when sync charts

[SSmallMonster]

We now have a scenario for synchronizing chart that uses charts-syncer.

Why we need this?

We need to add some custom classification properties to the synchronized chart to indicate different purposes.

Our method is to adds some custom annotations to the target Chart.yaml, but they are not currently supported in charts-syncer.

# Annotations in Chart.yaml
apiVersion: The chart API version
...
annotations:
  updateTime: "xxxx"

What we want?

Adding a chart field in the config file. This will greatly help users manage charts during synchronization.

# config.yaml used by charts-syncer
source:
...

target:
  chart:
      annotations:
          updateTime: "xxxx"

charts:
 - xxx
 - xxx

[kurt784]

Thanks for sharing. I found a lot of interesting information here. ADP Vantage Hcm