Updated STIG Manager entry, added stigman-watcher and stig-manager-client-modules

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Checklist

I have…

[ ] run the application locally (./scripts/serve) and verified that my changes behave as expected.
[ ] run the build process locally (./scripts/build) and make sure it builds correctly.
[ ] run the test suite (./scripts/test) and verified that all tests pass.
[x] summarized below my changes and noted which issues (if any) this pull request fixes or addresses.
[ ] thoroughly outlined below the steps necessary to test my changes.
[ ] attached screenshots illustrating relevant behavior before and after my changes.
[ ] read, understand, and agree to the terms described in CONTRIBUTING.md.
[ ] added my name, email address, and copyright date to CONTRIBUTORS.md.

This pull request…

To verify the changes proposed in this pull request…

Getting a gemfile conflict when running bundle install as described in "Getting Started" section of contribution guide , unable to test.
No changes to website code, just new .json files describing additional OSS repos.