Improve repohealth scores

Similar to OpenSSF, there is [repohealth](https://repohealth.tools/) which gives scores to improve the health of open source repositories.

All of this is optional. The higher the score, the better perception supposedly.

Here is the result

```bash
$ go install github.com/spbuilds/repohealth/cmd/repohealth@latest
$ export PATH="$HOME/go/bin:$PATH"
$ which repohealth
/Users/user/go/bin/repohealth
$ gh repo clone cloudposse/atmos
$ cd atmos/
$ repohealth

RepoHealth v0.5.2

Repository: /Users/user/git/github/atmos
Languages: Go (93%), TypeScript (2%), CSS (1%), JavaScript (1%)
Analyzed: 10473 files in 765ms

──────────────────────────────────────────────

Overall Score: 83 / 100 Grade: B+

──────────────────────────────────────────────

Documentation 8 / 15
README exists ✓ README.md found
README has content ◐ README has content but lacks key sections
LICENSE exists ✓ LICENSE found
CONTRIBUTING exists ✗ No CONTRIBUTING file found
CODE_OF_CONDUCT exists ✗ No CODE_OF_CONDUCT file found
SECURITY.md exists ✗ No SECURITY.md found
CHANGELOG exists ✗ No CHANGELOG found

Testing 20 / 20
Test files detected ✓ 2399 test files
Test directory exists ✓ demo/casts/atmos.d/demo/fixtures/tests/
Test framework configured ✓ go test (built-in)
Coverage config exists ✓ codecov.yml
Test-to-source ratio ✓ 2399 test files / 2357 source files (102%)

CI/CD 15 / 15
CI configuration exists ✓ GitHub Actions
CI runs tests ✓ Test command found in CI
CI runs linter ✓ Linter found in CI
CI runs build ✓ Build command found in CI

Dependencies 8 / 9
Lockfile exists ✓ go.sum found
Package manager detected ✓ go.mod found
Lockfile freshness ✓ go.sum updated within 90 days
Dependency count ✗ 177 dependencies declared

Security 5 / 10
No secrets in repo ✗ Generic secret assignment detected
.gitignore covers secrets ◐ .gitignore covers some but not all secret patterns
Dependency pinning ✓ go.sum pins dependency versions
Branch protection indicators ✓ .github/CODEOWNERS found

Code Statistics 5 / 5
Source files exist ✓ 2357 source files
Language diversity ✓ 7 languages
Comment ratio ✓ 17% comment ratio
No vendor bloat ✓ No vendor bloat detected

Activity 15 / 15
Recent commit ✓ today
Commit frequency ✓ 524 commits in last 6 months
Contributors ✓ 86 contributors
Release exists ✓ 968 release tags
Bus factor ✓ bus factor 3

TODO / Technical Debt 4 / 7
TODO/FIXME count ✗ 147 TODO/FIXME markers found
TODO density per KLOC ✓ 0.1 TODO/FIXME markers per KLOC
No critical TODO markers ✓ No critical TODO markers found

──────────────────────────────────────────────

Suggestions (sorted by impact)
+4 pts Remove secrets from source code and use environment variables
+3 pts More than 20 TODO/FIXME markers found — consider tracking them as issues
+2 pts Add a CONTRIBUTING.md with contribution guidelines
+2 pts Add a SECURITY.md with vulnerability reporting instructions
+1 pt High dependency count — audit for unused or redundant packages
+1 pt Expand README with installation, usage, and example sections
+1 pt Add a CODE_OF_CONDUCT.md (Contributor Covenant recommended)
+1 pt Add a CHANGELOG.md to track releases
+1 pt Add .env, *.pem, *.key, and credentials entries to .gitignore

──────────────────────────────────────────────

Improvement Plan
83 → 87 Remove secrets from source code and use environment variables
87 → 90 More than 20 TODO/FIXME markers found — consider tracking them as issues
90 → 92 Add a CONTRIBUTING.md with contribution guidelines
92 → 94 Add a SECURITY.md with vulnerability reporting instructions
94 → 95 High dependency count — audit for unused or redundant packages
```