I want to create a list in Markdown, but without bullet points. Is that possible?
The only recommended ways I found so far are using HTML, which I want to avoid.
No, with pure markdown this is not possible.
Think of Markdown as a simpler syntax for HTML. To change the styling you'll need to add a CSS to the generated HTML.
This might sound obvious but... you could understand a list as "lines separated by line breaks" (when you think about the output, not the markup).
First item (<-- two spaces)
Second item
This will render to:
First item
Second item
This looks like a list with no bullet points :)
A more beautiful example.
I know this isn't really specific to Github, but, if that were the case, you could then leverage the native CSS styling there:
<div id="user-content-toc">
<ul>
...
</ul>
</div>
Like @mb21 specified, here is the CSS if someone needs:
ul {
list-style-type: none;
margin-left: 40px;
}