Add geographic coordinate detection feature

[riazation42]

Description

Adds support for detecting geographic coordinate pairs (latitude, longitude) in decimal degree format.

Related Issue

Fixes #161

Changes Made

• Added COORDINATE data type constant in index.js
• Implemented isCoordinate() validation function with lat/long range checks (-90 to 90, -180 to 180)
• Added coordinate pattern to PATTERNS using precise regex validation
• Updated TypeScript definitions in index.d.ts
• Added 10 comprehensive tests covering valid/invalid coordinates, edge cases
• Updated README.md with coordinate examples and documentation

Checklist

Required (PR will not be merged without these):

• ✅ Synced with latest main branch (git rebase main)
• ✅ All tests pass (npm test)
• ✅ Linting passes (npm run lint)
• ✅ README.md updated with:
  • Data type added to supported types list
  • Test count updated (113 → 123)
  • Usage example added
• ✅ TypeScript definitions added in index.d.ts
• ✅ JSDoc documentation added for new functions

Code Quality:

• Followed conventional commit format (feat:, fix:, docs:)
• Used single quotes (') not double quotes (")
• No console.log statements in code
• Functions added at the end of file (minimizes conflicts)
• Test cases added at the end of test file
• Pre-commit hook ran automatically (auto-fixed linting)

Test Results

123 passing (86ms)

All existing tests pass + 10 new coordinate detection tests:

• Valid decimal degree coordinates
• Boundary values (90, 180, -90, -180, 0, 0)
• Various spacing formats
• Out-of-range latitude/longitude rejection
• Three-number string handling
• Integration with infer() function

Examples

const predictDataTypes = require('predict-data-types');

predictDataTypes('40.7128, -74.0060');
// { '40.7128, -74.0060': 'coordinate' }

predictDataTypes.infer('51.5074, -0.1278');
// 'coordinate'

predictDataTypes.infer('91.0, 0.0');  // Out of range
// 'string'

Avoiding Conflicts

• I have rebased on the latest main branch before creating this PR
• I understand that if conflicts occur, I need to resolve them by rebasing again