Add Latte template engine extension

[josbeir]

This adds initial support for the Latte template engine (PHP)

• Tree sitter: tree-sitter-latte
• Extension: https://github.com/josbeir/zed-latte
• Syntax highlighting, brackets, outline, indents.
• Emmet LSP enabled

[Copilot]

Pull Request Overview

This PR adds support for the Latte template engine (PHP) to Zed by integrating the zed-latte extension as a git submodule. The extension provides syntax highlighting, bracket matching, outline support, indentation, and Emmet LSP functionality for Latte template files.

• Adds the zed-latte extension as a git submodule
• Registers the Latte extension in the extensions configuration
• Configures the extension with version 0.1.0

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
extensions/latte	Adds the zed-latte extension as a git submodule
extensions.toml	Registers the Latte extension with version 0.1.0
.gitmodules	Configures git submodule for the Latte extension repository

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