Variable names must begin with a letter or underscore

[AlirieGray]

Small change to Variable name validation, documentation may be helpful. Users will see a clear error if they try to make an invalid Variable.

Relevant URLs

influxdata/influxdb#19317

[pierwill]

Does this change need to be documented in the InfluxDB docs, Flux docs, or both? @AlirieGray @sanderson

[AlirieGray]

I think just InfluxDB. It's already noted in the Flux docs that an Identifier must start with a letter or underscore, but it should be also noted for InfluxDB users creating Variables.