Add Lerd support

[geodro]

Adds Lerd to the list of detectable PHP environments, alongside Sail, Lando, and DDEV.

Lerd is an open-source, Herd-like local PHP development environment for Linux and macOS that runs Nginx, PHP-FPM, and services as rootless Podman containers. It exposes lerd php to run PHP inside a project's container, which is all the extension needs to resolve the environment.

The entry follows the existing containerized pattern:

• check: lerd php -r "echo PHP_BINARY;" to detect that Lerd manages the project
• command: lerd php
• relativePath: true, since PHP runs inside a container

One simplification worth noting: Lerd bind-mounts the project at its identical host path and runs lerd php with the container working directory set to the project root, so host and container paths line up 1:1. That means Lerd needs no entry in pathForPhpEnv, unlike DDEV which strips its /var/www/html/ prefix.

The Laravel.phpEnvironment enum, labels, and descriptions in package.json are updated to match, mirroring what generate-php-envs.php produces from the new entry.

[geodro]

@joetannenbaum sorry for the ping, I know the queue is long. This one is small, same shape as the Sail and DDEV entries, no conflicts.

lerd has grown quite a bit since July, around 1.2k stars now, and people on Linux keep hitting the extension not resolving their PHP.

The only difference from the others is that lerd bind-mounts at the same path as the host, so it doesn't need a pathForPhpEnv entry like DDEV does. If you'd rather keep all environments consistent there I can add one.