[README.md] Suggest the curl | bash installer

[mmmarinho]

What

Adds a One-line installer subsection at the top of Ubuntu Installation, pointing at jazzy/install.sh via raw.githubusercontent.com, and keeps the existing manual apt-get instructions below it as the alternative.

curl -fsSL https://raw.githubusercontent.com/SmartArmStack/smart_arm_stack_ROS2/lyrical/jazzy/install.sh | bash

Why

The manual block is 6 lines of key/source/install steps that are easy to get wrong, and it duplicates what install.sh already does idempotently. smart_arm_stack_ROS2 PR #12 makes that script safe to pipe into bash from a normal interactive shell: it validates sudo credentials up front (so the password prompt works when stdin is a pipe), detects the Ubuntu codename and architecture instead of hardcoding noble, installs the OSRF Gazebo source its own packages need, and never runs apt-get upgrade/autoremove.

Choices worth confirming

• URL uses the lyrical ref plus the jazzy/ subdirectory. lyrical is the repository default branch, so the link is stable and does not depend on branch naming. Note that jazzy/install.sh (on the jazzy branch) is the old 17-line version and still fails: it adds no OSRF Gazebo source, so ros-jazzy-sas-robot-driver-gazebo dies on unmet libgz-math7-dev/libsdformat14-dev. I verified both commands in ghcr.io/marinholab/ros:jazzy — the jazzy-ref one fails, the lyrical/jazzy/ one installs cleanly.
• Scope is stated explicitly: LGPL packages only, and ROS 2 plus DQ Robotics remain pre-requisites, since the script does not add the ROS 2 apt source.
• Mentions -n for a dry run and that re-running is safe.

Not done

No CHANGELOG.md entry — that file holds personal project-history notes rather than release notes. Say the word if you want one.

This PR was created by an AI agent (OpenHands) on behalf of Murilo Marinho.

[mmmarinho]

Verification notes

• Build checked locally: ran the same steps as build_html.yml (pre_build.sh + myst build --html) in node:18 against this branch — the site builds clean and the new One-line installer section renders (heading, code block, and note all present in index.html).
• The deploy check failure on this branch is expected noise, not a regression: the workflow is triggered by on: [push, ...], and actions/deploy-pages@v4 refuses to deploy from a non-production branch. It will pass on the push to main after merge. If you'd rather PR pushes don't turn red, restricting the trigger (on: push: branches: [main]) would do it — happy to fold that in if you want.
• Install command tested in ghcr.io/marinholab/ros:jazzy: the lyrical/jazzy/install.sh URL in the README installs end-to-end. The same path on the jazzy branch still fails on ros-jazzy-sas-robot-driver-gazebo unmet deps (no OSRF Gazebo source), which is why the link points at the default branch.

This comment was generated by an AI agent (OpenHands) on behalf of Murilo Marinho.

[mmmarinho]

👍

[mmmarinho]

👍