What does this PR do?

Improve repo

For resources

Description

Added a small definition about programming/coding playgrounds for making it understandable to beginners

Why is this valuable (or not)?

Copy the definition merged in #6822 into the rest of CONTRIBUTING files, opening a 3 weeks window to translate it by our comunity

Checklist:

• Read our [contribu

Describe the proposed change(s).

It seems to be available starting from Node v17. See also:
https://developer.mozilla.org/en-US/docs/Web/API/structuredClone

This action doesn't require debug mode. A user can optionally add it as a precondition to a keyboard shortcut if they so choose.

Whiskers' regex looks for <..> as opposed to tokenizing the input, so it is not able to detect truncated/mistyped input.

For example it can't detect that <!b is not terminated in<?b> X <!b Y </b>.

With some heuristics it could be improved: match for <?, <! and </ and only allow identifiers which are terminated with >, otherwise it is invalid.

_Originally posted by @axic in h

As discussed in the FE variety meeting, we should nest certain common components within the same directory. You can read more about this decision, here.

Examples of component types which can all co-exist in common directories include:

• modals, e.g. in a folder called modals
• dialogs, e.g. in a folder called `d