Update secretkeywords.txt

As requested ~ danielmiessler#267 (comment)

Merge pull request danielmiessler#225 from g0tmi1k/fixes

Fixes

Merge pull request danielmiessler#211 from melardev/add-resolvers-txt

Resolvers file for subdomain brute force

Merge pull request danielmiessler#180 from g0tmi1k/structure

Structure Clean Up (v2) & Issue fixes!

Added (overdue) credit for Michael Hendriksen.