Typo in the jobs_instances page

[lhajouji]

Hello,

There is a typo in the documentation for the extra-scrape-metrics feature flag. The word "additional" is misspelled as addditonal with an extra d and a missing i in the second syllable.

The related page

jobs_instances/

Current Text:

With the [extra-scrape-metrics feature flag](https://github.com/docs/prometheus/latest/feature_flags/#extra-scrape-metrics) several addditonal metrics are available:

Corrected Text:

With the [extra-scrape-metrics feature flag](https://github.com/docs/prometheus/latest/feature_flags/#extra-scrape-metrics) several additional metrics are available: