Add "spin cli" command

[jaydrogers]

👉 Describe the problem

• I want to run something like composer, but the project does not have spin configured or anything Docker related
• I cannot really do anything easily, or I need to type in some hideous command like below to run something as simple as composer install:

docker run --rm -v $(pwd):/var/www/html serversideup/php:8.1-cli composer install

👥 Problem evidence & reach

Users getting started with Spin or users dealing a lot with new projects may have this problem.

🥰 Describe the "impact" on users?

Solving this will make users less frustrated when dealing with new

🏆 How to solve this problem

Add a spin cli command

This would be a command that would use our standardized docker images to get started.

For example:
This command:

spin cli php 8.1 composer install

Would basically run:

docker run --rm -v $(pwd):/var/www/html serversideup/php:8.1-cli composer install

Breaking the command down:

spin cli {{service} {{version}} {{command-to-run}}

The above command will allow users to quickly run common tasks from trusted images without the headache of configuring environments or installing versions manually on their computer.

💯 How do we validate the problem is solved?

• spin cli is added and documented