Extend logTime to nanosecond precision

[roryrjb]

Hello! Thanks for the handy syntax file.

These days I'm mostly looking at logs from Kubenetes pods. Using kubectl you can specify the --timestamps=true flag which will prefix all log entries with the timestamp they were recorded. Anyway this seems to be at nanosecond granularity, e.g.

2023-08-17T07:52:26.131134150Z Generating output directory: dist/
2023-08-17T07:52:26.144996867Z Full static mode activated
2023-08-17T07:52:26.146209081Z Generating pages

This change just extends the logTime regex up to 9 digits. Please consider merging it in, many thanks!