docs(sim): add Try PX4 quick-start and pre-built packages reference

[mrpollo]

Adds documentation for the SITL containers and .deb packages introduced in #26495. The containers are now live on Docker Hub: px4io/px4-sitl:latest and px4io/px4-sitl-gazebo:latest.

The main addition is a Try PX4 Simulation page that leads with a single docker run command and gets someone flying in under a minute. It lives in Getting Started, right after Recommended Hardware/Setup, so it's one of the first things new users see.

The existing .deb package reference has been moved from packaging/px4_sitl_deb.md to simulation/px4_sitl.md and expanded to cover both containers and .deb packages on one page. Sections are ordered by how people use them: what's available, install, configure, connect QGC/MAVSDK, connect ROS 2.

Other changes:

• README now has a "Try PX4" section with the docker one-liner above "Build from Source"
• Landing page (index.md) reworked to lead with "Try PX4" before "For Developers"
• Toolchain page (dev_env.md) gets a tip redirecting simulation-only users to pre-built packages
• getting_started.md and SUMMARY.md updated with links to the new pages
• Simulation index tip updated to mention containers alongside .deb packages

The SIH container image is published as px4io/px4-sitl (renamed from px4io/px4-sitl-sih) so the default lightweight option carries the simplest name. The Gazebo image remains px4io/px4-sitl-gazebo.

Also upgrades all GitHub Actions in the SITL workflow to Node.js 24 compatible versions (actions/checkout@v6, actions/cache@v5, actions/upload-artifact@v7, actions/download-artifact@v8, docker/setup-buildx-action@v4, docker/build-push-action@v7) to fix the Node.js 20 deprecation warning ahead of the June 2026 deadline.

[github-actions]

/en/sim_sih/index.md

• LinkedInternalPageMissing: This linked file is missing: px4_simulation_quickstart.md

[mrpollo]

@farhangnaderi, could you put your academic hat on, forget everything you know about PX4 for a second, and try to go through the docs on this PR? It introduces a new SITL container (~30mb) that can run SITL. I'm being kinda bold here and promoting this feature as "try PX4 in 1 easy step."

[github-actions]

💡 Commit messages could be improved

Not blocking, but these commit messages could use some cleanup.

Commit	Message	Suggestion
a4bc3a2f20	Rename the files and simplify the quickstart	Missing conventional commit format (e.g. "feat(ekf2): add something")
59bfcc7661	Fixes for quickstart and move it up top	Missing conventional commit format (e.g. "feat(ekf2): add something")
334e9fb915	Minor comments	Missing conventional commit format (e.g. "feat(ekf2): add something")
696d9ba3fd	Apply suggestion from @hamishwillee	Missing conventional commit format (e.g. "feat(ekf2): add something")

See the commit message convention for details.

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This comment will be automatically removed once the issues are resolved.

[mrpollo]

@hamishwillee, your edits make sense to me. I also merged my work and renamed the container image from px4-sitl-sh to px4-sitl, which makes it easier to remember too. Lastly, the IPv6 issue is already fixed. Let me know if you can try the instructions and if you succeed.

[hamishwillee]

@mrpollo I cut back the quickstart now it is in the intro and the development stuff doesn't belong. The cut out information was already in the prebuilt package topic, so I see not loss. I've fixed up the other open questions.

I tried running the SIH container. It starts clean and fast. I couldn't connect to it, but the error looks like a local problem with the UDP port (I am hammering lots of things at the moment). I will try again tonight, but I am approving because I think this is good. Not merging because you might want to have other review or testing.

After this we do need to add the hawkeye stuff - ideally in that same container and ideally linked into the SIH start.

[mrpollo]

This is amaziiiiing 🏆

[farhangnaderi]

@mrpollo Sorry I wasnt notified by this. Thank you very much for your effort. I like this.

As a new comer I tried running and these are what I experienced:

1. It is a one step IF you know docker. (I had the permission denied error which needs docker to be added to user group)
2. docker run --rm -it -p 14550:14550/udp px4io/px4-sitl:latest already hooks to a port and QGC doesnt bind on Linux. but docker run --rm -it --network host px4io/px4-sitl:latest works which means I had to go and check the extra steps.

So maybe for the quickstart:

PX4 Simulation QuickStart

First install Docker (a free tool that runs containers).
The following command will then run a PX4 quadrotor simulation that you can connect to QGroundControl, MAVSDK or ROS 2 (on Linux, macOS, and Windows):

docker run --rm -it --network host px4io/px4-sitl:latest

That's it — open QGroundControl and fly!

::: warning Troubleshooting
"Permission denied" error (Linux)
Add your user to the docker group:

sudo usermod -aG docker $USER
newgrp docker

Then run the docker command again.

:::

::: tip
To try other vehicle types append the corresponding line below to the command:

-e PX4_SIM_MODEL=sihsim_airplane # Plane
-e PX4_SIM_MODEL=sihsim_standard_vtol # Standard VTOL
-e PX4_SIM_MODEL=sihsim_rover # Ackermann rover

For more information and options see Container Images (in Pre-built SITL Packages) and SIH Simulation.
:::

[mrpollo]

Thanks @farhangnaderi, regarding docker/containers, you right that we are expecting users to have docker already setup, and some hints as to how to troubleshoot might be nice, but maybe not in the quickstart page.

On the --network host vs specifying ports, that was actually the first problem I ran into, it would have been super nice to just have the one liner, but the -p should have worked for everyone assuming no port conflicts. Maybe what we should do here is to have a tab component to keep the page clean. This way we only show one command by default, and hide the other in a tab, a tab for Linux and another for macOS/Windows, whoever I'm not sure we have such component in the docs

[hamishwillee]

This is really good. I've always thought we needed an easy way for no brainer testing and now we have it.

I tried --network host and that option does not bind on my computer - silently no connection. The port does.

A tab might work. But probably a details twistie better. Say as little as possible. Link to docker debugging info elsewhere.

::: details Troubleshooting
Blah vlah
:::