If the code in the editor is code that you wrote, yes go ahead and execute it. If you opened that challenge from a link in a forum or chat, I would use the button to reset the code.
fCC contributors built that feature recently to protect against 3rd-party code execution in your browser. They’re debating how to handle it long term. https://github.com/freeCodeCamp/freeCodeCamp/issues/16565
When in doubt… click the reset button. 
Lets have one more important query that everyone should know?
Which is Better?
Internal CSS or External CSS?
Explain with reasons.
Does anyone else think that the picture illustrating the anchor tags is a bit confusing for beginners?
I think the arrows are too thick, and aren’t closely linked enough with their associated explanation (the line is too far away).
Also, the sections on labels is unclear -
It is considered best practice to set the for attribute for assistive technologies to be able to link the relationship between the label and the child elements such as an input in this case.
<label for="indoor">
<input type="radio" name="indoor-outdoor">Indoor
</label>
I don’t think it clearly explains what a label is for, what assistive technologies are in relation to html, or what is meant by linking the relationship of label and child element.
It think it would be clearer if the <id> tag was covered before introducing radio buttons, which would allow the use of implicit linking (as above) as well as an example where the relationship is explicit:
<label for="option one">option-one</label>
<input type="radio" id="option one" name="options">
and a quick example of screen-readers was given for assistive technologies.
Hope this doesn’t come across snarky or pedantic 
If there is a better place to post suggestions/corrections of the beta content let me know, as I realise this thread is probably more for discussion of the content itself.
edit: also, enjoying the updated content so far! 
@silentgamelan Thanks for the comment! 
You can file an issue by following the contribution guide. Also, in terms of the label element specifically, I noticed that the fCC Guide entry for label doesn’t exist yet. You may want to contribute to the guide by adding that section.
cheers, I’ll have a look at those links later tonight - glad to help
@silentgamelan @camper check out this GitHub issue that I opened to address part of this issue.