[docs] Add prerequisite tests for modules in Foundations of DevOps and SRE learning path

[Copilot]

Notes for Reviewers

This PR fixes the missing prerequisite tests for individual modules within the Foundations of DevOps and SRE learning path. Previously, only course-level tests existed.

Changes

Added 6 module-level test.md files with 5 questions each:

Introduction to DevOps and SRE course (4 modules):

• introduction/test.md - DevOps/SRE fundamentals and definitions
• what-is-devops/test.md - Core concepts and terminology
• pre-devops/test.md - Pre-DevOps era characteristics (Waterfall, silos, manual processes)
• devops/test.md - DevOps principles (CI/CD, IaC), tools (Kubernetes), and AI trends

Site Reliability Engineering course (2 modules):

• sre/intro/test.md - SRE objectives, metrics (SLIs/SLOs/SLAs)
• sre/sre/test.md - SRE principles, error budgets, blameless postmortems

Each test follows the existing format: 70% pass threshold, mix of single-answer and multiple-answers questions, content aligned with module objectives.

Signed commits

• Yes, I signed my commits.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Prequisite tests missing for modules in Foundationsn of devops and sre learning</issue_title>
<issue_description>### Current Behavior

Based on each modules content in the Foundationsn of devops and sre learning path define a small test with 5 questions for each module

Expected Behavior

Screenshots/Logs

Environment

• Host OS: Mac Linux Windows

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Comments on the Issue (you are @copilot in this section)

• Fixes Prequisite tests missing for modules in Foundationsn of devops and sre learning #186

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