Add detailed README for Gripmock Types package

[rez1dent3]

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[Copilot]

Pull Request Overview

This PR creates a new Go package called "Gripmock Types" that provides custom JSON serialization types for the Gripmock project. The package addresses a specific issue where JSON strings representing durations (like "100ms") could not be properly deserialized into Go's time.Duration type.

• Implements a custom Duration type with JSON marshaling/unmarshaling support
• Adds comprehensive test coverage for the new Duration type
• Includes complete project setup with CI/CD workflows, linting configuration, and documentation

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
go.mod	Defines the Go module with Go 1.24 requirement
duration.go	Implements the custom Duration type with JSON support
duration_test.go	Provides comprehensive test coverage for Duration type
README.md	Documents the package purpose, usage, and installation
Makefile	Defines build tasks for testing and linting
.golangci.yml	Configures Go linting rules and formatters
.github/workflows/unit.yml	Sets up CI for running tests on multiple Go versions
.github/workflows/golangci-lint.yml	Configures automated code linting
.github/workflows/semgrep.yml	Sets up security scanning
.github/workflows/changelog.yml	Automates changelog generation
.github/dependabot.yml	Configures dependency updates

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