Sync README.en.md with last two commits to README.md

[Copilot]

README.en.md was out of sync with two recent commits that updated the Docker Engine installation section of README.md.

Changes

From de385d4 (missed entirely):

• Moved "For other Linux distributions" note to appear before the install commands block
• Updated install commands: apt-get → apt
• Replaced old echo | sudo tee docker.list repository setup with the current DEB822 format:

  sudo tee /etc/apt/sources.list.d/docker.sources <<EOF
  Types: deb
  URIs: https://download.docker.com/linux/ubuntu
  Suites: $(. /etc/os-release && echo "${UBUNTU_CODENAME:-$VERSION_CODENAME}")
  Components: stable
  Signed-By: /etc/apt/keyrings/docker.asc
  EOF

• Removed the obsolete "Add Docker's repository to Ubuntu's sources list" block (old curl | gpg --dearmor method)

From 3aa8640 (partially applied):

• > **For other Linux distributions** heading format (was > **NOTE:**)
• Replaced "Re-access Ubuntu and start Docker" with auto-start note + service docker status check + service docker start for manual fallback
• Added missing hello-world post-install verification step with expected output in a code block

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[Copilot]

Pull request overview

Synchronizes README.en.md with recent updates to the Docker Engine installation instructions so the English README matches the current Ubuntu/WSL2 Docker setup flow.

Changes:

• Moves the “For other Linux distributions” note above the Ubuntu-specific install commands.
• Updates Ubuntu install steps to use apt and Docker’s current DEB822 (docker.sources) repository configuration.
• Improves post-install guidance: service status/start instructions and a hello-world verification step.

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[Copilot]

The command in this code block has an extra leading space before sudo, which makes copy/paste inconsistent with the other command blocks in this section. Remove the leading whitespace so the command is flush-left inside the fenced block.

[Copilot]

This code block also has an extra leading space before sudo. Please remove it to keep command examples consistent and avoid copying a leading space into shells/tools that treat it specially.

[Copilot]

The expected hello-world output snippet is inaccurate/ill-formed: it starts with a double quote but never closes it, and the real Docker output does not include surrounding quotes. Update the snippet to match the actual docker run hello-world output format (no quotes) and ensure it’s syntactically consistent.

Suggested change

	"Hello from Docker!
	This message shows that your installation appears to be working correctly..."
	Hello from Docker!
	This message shows that your installation appears to be working correctly.