[InfluxDB] Update influx_inspect documentation with dumptsi command

[rkuchan]

Add content about the dumptsi command to the influx_inspect documentation, under the sample data section:

influx_inspect dumptsi [<flags>] <path>

Dumps low-level details about tsi1 files.
dumptsi returns summary stats for each file if the command does not specify any flags.

Flags

-series

Dump raw series data.

-measurements

Dump raw measurement data.

-tag-keys

Dump raw tag keys.

-tag-values

Dump raw tag values.

-tag-value-series

Dump raw series for each tag value.

-measurement-filter <regular_expression>

Filters data by measurement regular expression.

-tag-key-filter <regular_expression>

Filters data by tag key regular expression.

-tag-value-filter <regular_expresssion>

Filters data by tag value regular expression.