[FEATURE] Add examples directory and root .dockerignore

[Ayush7614]

Summary

Add an examples/ directory with sample Dockerfiles for learning and local testing, plus a root .dockerignore so docker build stays fast and does not send .venv into the build context.

The CHANGELOG (v0.x) already documents a "Complete Examples Directory", but that folder is not present on main today. This issue tracks adding it back.

Problem Statement

• New users lack runnable sample Dockerfiles to compare secure vs vulnerable patterns.
• Local docker build for the project Dockerfile is very slow without .dockerignore because .venv (~300MB) is included in the build context.
• README and getting-started docs reference examples in templates/issues but there is no examples/ path in the tree.

Proposed Solution

1. examples/ directory

Example	Purpose
python-flask-secure/	Hardened Python: pinned base, non-root user, health check
nodejs-vulnerable/	Intentional misconfigurations for education (not for production)
golang-multistage/	Multi-stage build with distroless runtime

Each subfolder should include:

• Dockerfile
• Minimal app source
• README.md with docksec scan commands

Top-level examples/README.md with a short learning path.

2. Root .dockerignore

Exclude at minimum:

• .venv, .git, __pycache__, .env, tests, docs, build artifacts

3. Documentation

• Link examples/ from root README.md Quick Start
• Add an Examples section to tab_gettingstarted.md

Example usage:

# Scan only (no API key)
docksec examples/nodejs-vulnerable/Dockerfile --scan-only

# Build and scan Go example
docker build -t docksec-example-go:local examples/golang-multistage
docksec examples/golang-multistage/Dockerfile -i docksec-example-go:local --scan-only

Alternatives Considered

• Document examples only in README without files in-repo (harder to run and test).
• Single example instead of three (less useful for comparing secure vs vulnerable outcomes).

Use Case

• Individual developers
• DevOps teams
• Security teams
• CI/CD pipelines
• Enterprise users

Acceptance Criteria

• examples/ contains three documented sample projects with scan instructions
• Root .dockerignore prevents .venv from bloating Docker build context
• README links to examples/README.md
• Hadolint/Trivy scans run successfully against at least one example (documented in PR)

Implementation Notes (local validation)

Validated locally on macOS (Docker, Hadolint, Trivy, Docker Scout):

Example	Scan mode	Approx. score
nodejs-vulnerable	Dockerfile only	76.5
python-flask-secure	Dockerfile + image	49.5 (image CVEs)
golang-multistage	Dockerfile + image	48.0 (Go stdlib CVEs in binary)

Implementation is ready on branch ayush1 for a follow-up PR if maintainers agree.

Related Issues

• Referenced in .github/ISSUE_TEMPLATE/question.md (examples directory link)
• Documented in docs/CHANGELOG.md but missing from repository tree

[Ayush7614]

cc: @advaitpatel

[advaitpatel]

Thank you for your feedback @Ayush7614 ! I will work on this as soon as I can.