Instruction in Example Guide may describe wrong behavior

[KatieWoe]

Device
Dell
OS
Win 11
Browser
Chrome
Problem Description
For phetsims/qa#820
Under the section for Mass Properties under the mystery screen, it says this:

To set the mass, use the massProperty. When customizing the mass, the volume will remain constant and the material/density will be updated.

However, the volume seems to change and the density is kept constant instead. I'm not sure if this is an issue with the guide or with the behavior, so assigning @arouinfar as well as @jonathanolson.

Visuals

[arouinfar]

@jonathanolson this isn't the intended behavior, and the Examples doc is consistent with the phetioDocumentation of the massProperty which states:

Current mass of the block. Changing the mass will result in changes to the material (and therefore density), but the volume will remain the same.

[jonathanolson]

My impression was the intended behavior is for the volume to update when mass is changed (especially for phet-io changes). Is that the desired behavior for this?

Work for #101 notes the desire to change the volume, and the Mystery screen has the option adjustMassWithVolume set to true.

If that's not the desired behavior, it might be a significant amount of work.

[arouinfar]

Thanks @jonathanolson, I was mistaken. I've updated examples.md to describe the correct behavior.

Due to the changes made in #138 to set volumeProperty.rangeProperty to [1, 10] L, if users aren't careful when setting massProperty they could create a situation where volumeProperty becomes out of range causing the sim to reload.

For example:

1. Set customDensityProperty to 10000 kg/m^3
2. Set massProperty to 1000 kg
3. The required volume is 100 L, which is out of range.
   
4. When the sim reloads, the massProperty becomes 100 kg which corresponds to the maximum allowed volume (10 L).

It seems like Studio otherwise restores the state correctly, so users are unlikely to lose their work. I think we made the right call in #138, so I added further clarification to examples.md for this case.