updates to the label normalization tool

[devoncarew]

Updates to the label normalization tool:

• add a few more common labels synonyms (these help the tool know what to rename labels to)
• add an alias for the --dry-run flag (--audit) and the --apply-changes flag (--apply)
• increase the repo circuit breaker from 200 issues to 300 (this lets us manage slightly larger repos)

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[natebosch]

What does this change accomplish? Can you include a bullet point about why this is changing in the commit message?

[devoncarew]

Yup - this lets us work on slightly larger repos. This circuit breaker is here so that we don't make automated changes to the bigger repos w/o really thinking about it (w/o having to do something like edit the tool's source). I'll add a bullet-point.