CI broken: htmlproofer reports spurious error

[rhaschke]

Since a few days htmlproofer is broken and reports this spurious error in realtime_servo_tutorial.rst:

    *  877:3: ERROR: Eng tag 'embed' isn't allowed here. Currently open tags: html, body, div, section, div, div, div, div, div, object.
    </embed>

Obviously, the corresponding source code is ok: https://github.com/ros-planning/moveit_tutorials/blob/9ad1fecf00f6f40588eb5c88508347f00affdd6c/doc/realtime_servo/realtime_servo_tutorial.rst?plain=1#L8-L15 The error was introduced by external changes or updates as the same commit that built successfully 5 days ago, now fails: https://github.com/ros-planning/moveit_tutorials/actions/runs/4977228410

I don't have time to tackle this. Hopefully, somebody from your team, @davetcoleman / @henningkayser, can have a look. I suggest updating the workflow using the template from moveit2_tutorials.

Note that the htmlproofer job on moveit2_tutorials is broken too - but for different reasons.

[henningkayser]

We have seen something similar on the MoveIt website. https://github.com/ros-planning/moveit.ros.org/issues/803 And there is actually a bunch of broken html, partially in the layouts and partially due to markdown processing, so it seems. I didn't have too much time to look into it yet, but it's certainly reproducible locally and not really spurious at all.

[rhaschke]

I have seen the MoveIt2 issue, but it is unrelated. Here, the error reported by htmlproofer is definitely spurious. The generated HTML is perfectly fine.

[henningkayser]

The HTML is not really fine, the end tag is redundant and should be omitted (this is not the only reference that states this). #782 fixes this. So it really looks like htmlproofer just got more picky about everything, also the reported error doesn't really help too much.

[rhaschke]

Fixed via #782.