added "example" to detector badlist

[orionooooo]

Description:

Adds "example" to the list of stopwords

Checklist:

• [x] Tests passing (make test-community)?
• [x] Lint passing (make lint this requires golangci-lint)?

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[zricethezav]

@orionooooo just for posterity's sake, could you fill out the description of this issue? Also maybe provide an example of a secret you want to truffle to ignore via badlist.txt

[orionooooo]

@zricethezav sure, I just wanted to add the word "example" to the list because I noticed it wasn't there.

[zricethezav]

@orionooooo great, now next time you open a PR please fill in the description