Add an FYI that command block execution is quite broken if installed via snap

[sidju]

Describe the bug
When executing through snap the user's PATH variable is ignored, causing per-user applications to be inaccessible when executing command blocks and probably causing unexpected versions to be used of some tools.

This isn't in itself a bug, but imo. the absence of documentation to this fact is.

To Reproduce
Create a markdown document with a codeblock as follows:
bash env | grep PATH
The PATHs printed contains only standard system paths and snap's overrides, no user specific additions or changes.

Expected behavior
This should be clearly informed as a caveat to installing with Snap and as a gotcha where codeblock execution is described.

Desktop (please complete the following information):

• OS: Ubuntu

[mbrugnoni]

I'm having trouble executing commands that seem to be in the PATH even. For example, when I use env | grep PATH and run that on a slide, I get PATH=/snap/slides/487/usr/sbin:/snap/slides/487/usr/bin:/snap/slides/487/sbin:/snap/slides/487/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games

Then when I run something like cowsay, which is in /usr/games, I get exit status 127, which would indicate it's not found. All standard bash commands seem to work (ie. ls, echo).

Installed with snap on Ubuntu 22.04.5.

[res1st]

Same for me