Add gitty — human-readable Git/GitHub CLI wrapper

[Omibranch]

gitty

gitty is a single-binary CLI that wraps Git and GitHub into short, human-readable commands.

Core idea: `gitty up` replaces the entire `git add → git commit → git push` cycle in one word.

Highlights

• `gitty up` — stage, commit, and push in one shot
• Human-readable shorthand: `gitty push=main`, `gitty pull~main`
• Interactive conflict resolution: `gitty fix `
• Selective commits by line range or code markers
• Built in Go — single binary, zero external dependencies
• Runs on Linux (amd64/arm64), macOS, Windows

Fits in the For Developers section alongside other git workflow tools like `forgit`, `gita`, and `git-extras`.