🧪 Add Subject-Specific Hint Templates

## Description
Create hint templates for different subjects (Math, Science, Programming, etc.).

## Tasks
- [ ] Research effective hint strategies per subject
- [ ] Create template structure
- [ ] Implement templates for 5+ subjects
- [ ] Add examples for each template
- [ ] Document template usage

## Expected Outcome
Subject-specific hint templates that educators can use.

## Skills Required
- JavaScript/React
- Educational knowledge
- Template design

## Difficulty Level
🟡 Intermediate

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*Hacktoberfest 2025 - Feature enhancement*

No files, tests, or entry points are named. Begin by locating the existing hint-generation flow and deciding how templates are represented, then research subject-specific strategies before defining templates for at least five subjects. Done means educators can use the templates, each has examples, and template usage is documented.

Written by the indexing model from the issue text.