Docs (README): images not found in Syntax Highlighting Section

[almndbtr]

Summary

In the Syntax Highlighting section of the README, the last sentence reads:

Code fragments passively draw your attention to statements that typically reduce risk (#c5f015) or need your attention (#f03c15).

Neither of the cited (color?) hex codes render the intended images.

Checking the source, it seems the intent was to highlight "reduce risk" in green and "need your attention" in red:

Code fragments passively draw your attention to statements that typically <span style="color:green">*reduce risk* (![#c5f015](https://placehold.it/15/c5f015/000000?text=+))</span> or <span style="color:red">*need your attention* (![#f03c15](https://placehold.it/15/f03c15/000000?text=+))</span>.

I don't think that GitHub-flavored Markdown supports this in the way one would expect. Also, placehold.it seems unreachable today:

➜  ~ curl placehold.it
curl: (6) Could not resolve host: placehold.it

Perhaps using a different service would be more advantageous here, like via.placeholder.com? 💭

• #c5f015
• #f03c15