Content: docs: fix a little format thing

[tjcchen]

MDN URL: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Keyed_collections

What information was incorrect, unhelpful, or incomplete?

I am not sure if this is a little format issue( or a typo ) on the content at the bottom of the page. It is about WeakSets are not enumerable. line at the bottom of the page.

Specific section or headline?

WeakSets are not enumerable. content at the bottom of the page
Should prepend a bullet symbol at the beginning of this line I think, this could be a typo.
I think this PR could improve our great MDN documents a little. If this is not necessary, please ignore it.

What did you expect to see?

• WeakSets are not enumerable.

a bullet symbol is expected.

Did you test this? If so, how?

Yes, by adding this symbol with Markdown on my own computer.

MDN Content page report details

• Folder: en-us/web/javascript/guide/keyed_collections
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Keyed_collections
• GitHub URL: https://github.com/mdn/content/blob/master/files/en-us/web/javascript/guide/keyed_collections/index.html
• Report started: 2021-01-18T04:14:32.632Z

[tjcchen]

I think this PR could improve our great MDN documents a little. If this is not necessary, sorry for the bothering, and please ignore it. Thanks in advance!

[hamishwillee]

@tjcchen thanks for taking the time to post this - every little bit helps. Fixed in #1602

Note, you can also fix this kind of thing yourself and create a PR request. That saves us even more time :-)

[tjcchen]

Sure, thanks much for your reply and fixing, @hamishwillee. I will submit a PR next time. This is my first time to do a little contribution to our awesome MDN documentation, and I am unfamiliar with the fixing process.

Your comment did give me a hint on how to fix such issues, appreciate your kind help.

Btw, MDN documentation is really great and helpful in our daily development work. Kudos to your work!