Add Arch Linux (PKGBUILD) install support

[ashitaprasad]

API Dash currently has a Arch Linux package page (https://aur.archlinux.org/packages/apidash-bin) which was setup by a contributor. We have maintainer access to it, but currently lack the following:

1. Step by step details on how to create a build and release it.
2. CI/CD pipeline which prepares and publishes the build on Arch Linux package repository whenever pubspec.yaml version is bumped.

Developers are requested to add (1) in https://github.com/foss42/apidash/blob/main/doc/dev_guide/packaging.md

Once (1) is completed (2) can be taken up.

Related issues & discussions - #240

[nihalxkumar]

I'd like to help with both tasks. Here's my proposed approach:

1. I'll document the manual steps required to:

• Download and verify new release files
• Update the PKGBUILD with new versions and checksums
• Test build the package locally
• Update and publish to AUR

I'll make sure the documentation is: Clear enough for new maintainers, Follows AUR packaging best practices, Includes basic troubleshooting tips

2. CI/CD Pipeline:

Once the documentation is approved, I'll work on automating the process using GitHub Actions. The pipeline will:

• Monitor pubspec.yaml for version changes
• Update the AUR package

Will also try Testing and Auth if the pipeline worked well

Although, this will be my first attempt at pkg building and pkg documentation, I am familiar with the Arch and Linux ecosystem and the AUR is my daily go-to :)

[ashitaprasad]

Sounds good @nihalxkumar