Adds support for additional arguments in TailwindHostedService - #7

This pull request adds support for passing additional arguments to the Tailwind CLI process and improves test coverage to ensure these arguments are handled correctly. The main changes include updating the TailwindOptions class, modifying the hosted service to use the new option, and adding a new test.

Feature: Support for additional Tailwind CLI arguments

• Added a new property AdditionalArguments to the TailwindOptions class, allowing users to specify extra command-line arguments for the Tailwind CLI.
• Updated the TailwindHostedService to append AdditionalArguments to the CLI invocation if provided, ensuring they are included when starting the process.

Testing:

• Added a new unit test AdditionalArgumentsAreIncludedInProcessStart to verify that any additional arguments specified in TailwindOptions are correctly passed to the process.

Code cleanup:

• Removed an unused using Microsoft.Extensions.Configuration; directive from TailwindHostedService.cs.

Minor:

• Updated user settings in .DotSettings.user file to toggle session activity flags for unit test sessions.