document new series of internal_write measurement

Relevant telegraf.conf

[agent]
  hostname = "myserver"

[[inputs.internal]]
  namepass = ["internal_write"]

[[outputs.file]]
  files = [ "stdout" ]

Logs from Telegraf

internal_write,host=myserver,input=internal,version=1.32.3 startup_errors=0i 1738793420000000000
internal_write,host=myserver,output=file,version=1.32.3 write_time_ns=0i,startup_errors=0i,errors=0i,metrics_dropped=0i,metrics_added=0i,metrics_filtered=0i,metrics_written=0i,buffer_limit=10000i,buffer_size=0i 1738793420000000000

System info

Telegraf v1.32.3

Docker

No response

Steps to reproduce

1. Just run telegraf, wait a little and watch output telegraf --config internal_write.conf

Expected behavior

According to current README the output should be just: internal_write,host=myserver,output=file,version=1.32.3 write_time_ns=0i,startup_errors=0i,errors=0i,metrics_dropped=0i,metrics_added=0i,metrics_filtered=0i,metrics_written=0i,buffer_limit=10000i,buffer_size=0i 1738793420000000000

Actual behavior

This series is not documented in README: internal_write,host=myserver,input=internal,version=1.32.3 startup_errors=0i 1738793420000000000 It would be nice to document it just for the sake of completeness. Thanks.

Additional info

No response