Migrate data from OSS v1/v2 to InfluxDB 3 Enterprise

[jstirnaman]

We have a brief <https://docs.influxdata.com/influxdb3/enterprise/write-data/use-telegraf/dual-write/|Telegraf guide> about dual writing that suggests using it for migration:
> Use Telegraf to write your data simultaneously to multiple InfluxDB instances or clusters. This method, known as “dual writing,” is useful for backing up data to a separate instance or for migrating from other versions of InfluxDB to InfluxDB 3 Enterprise.
and we have very brief guides for API compatibility.

Add a page that's more explicit about the recommended steps and suggestions for historical data.

Slack Message

[idclark]

@jstirnaman I can help with this starting Monday. I think it's mostly just stitching together bits of snippets across our docs.

[temujin9]

A note about other source platforms (Cloud1 & Cloud2, primarily) would probably not go amiss.