222 improve installation questions

[JC-DSIT]

Proposed changes

What changed

• References to PaaS and supporting files have been removed.
• Installation questions changed to be more simple to understand
• Config uses more dynamic defaults

Related issue or tracking reference

You should have an open GitHub issue that this PR will fix.

• Fixes Improve installation questions #222

Include screenshots, logs, or rendered output if this change affects layout or behaviour.

Questions:

**What will the URL of your documentation be, for example https://example-docs.gov.uk?
You can change this later in config/tech-docs.yml.**
**Documentation URL:** https://my-new-documentation.gov.uk
**What is the name of the service or API your documentation is about, for example Data sharing service?
You can change this later in config/tech-docs.yml.
Service Name:** Fancy new service
**What is the URL for the service your documentation is about, for example https://new-service.gov.uk?
You can change this later in config/tech-docs.yml.
Service URL:** https://service-you-never-knew-you-needed.gov.uk
**Will you be using the GOV.UK logo?** no
      create  config/tech-docs.yml
       exist  source
      create  source/API-reference.html.md.erb
      create  source/get-started.html.md.erb
      create  source/how-the-api-works.html.md.erb
      create  source/how-to-do-a-task.html.md.erb
      create  source/index.html.md.erb
      create  source/support.html.md.erb
      create  source/test-your-integration.html.md.
1/lib/ruby/site_ruby/3.3.0/rubygems/platform.rb:288: warning: previous definition of X64_LINUX_MUSL was here
Bundle complete! 4 Gemfile dependencies, 62 gems now installed.

Resulting config

host: https://my-new-documentation.gov.uk

# Header-related options
show_govuk_logo: false
service_name: Fancy new service
service_link: https://service-you-never-knew-you-needed.gov.uk
phase: Beta

# Links to show on right-hand-side of header
header_links:
  About: https://service-you-never-knew-you-needed.gov.uk/about
  Get Started: https://service-you-never-knew-you-needed.gov.uk/get-started
  Documentation: https://my-new-documentation.gov.uk
  Support: https://service-you-never-knew-you-needed.gov.uk/support
...

Checklist

Before you request approval you should confirm that:

• the pull request has a clear title with a short description about the update in the documentation
• GitHub actions all pass
• you have tested the changes with a fresh build against the latest version of the tech-docs-gem
• you have linked this PR to an issue (or explained why none exists)
• you have updated documentation if needed

[jackhobson]

All looks good to me.