all charts to use helm upgrade --install instead of helm install ; helm delete --purge replaced by helm uninstall (helm3 compatibility)

It looks like an issue, based on _helpers.tpl, should be only one "-". 
This causes an error and influxdb setup with the localhost instead of filled value.

Disable debug, fix default output, add mention on the readme about the fact that inputs cannot be customised.

This chart does not allow tweaking the input configuration. It is for
node and Kubernetes monitoring.

Use the `telegraf` chart if you need to configure the inputs

https://github.com/updownpress/markdown-lint/blob/master/rules/014-commands-show-output.md

See https://github.com/updownpress/markdown-lint/blob/master/rules/014-commands-show-output.md

[influxdb] Backup restore readme

By copying /backup/* we are copying all contents, in this case the timestamped backup folder, without the prepending /backup