style guide for multiline html - html

Question

I have some lengthy HTML which is over the 80 character limit for my project. We have a style guide which restricts the number of characters per line, which is good because right now the line runs so long that you can't see it all without scrolling right.
<div id="email-signup-container">
<div id="mc_embed_signup">
<div class="interested">
<div class="container">
<div class="left col-lg-6 col-md-6 col-sm-12 col-xs-12">
<h3>Help New York residents keep the heat on this winter.</h3>
DONATE
</div>
<div class="right col-lg-6 col-md-6 col-sm-12 col-xs-12">
<h3>Without heat? Visit our resources page.</h3>
<a class="btn-interest" href="resources">RESOURCES</a>
</div>
</div>
</div>
</div>
</div>
Unfortunately, I can't find any style guides that cover multilining HTML. I worked on one project where we newlined things by attribute, but it was controversial:
<a
href="http://www.nycharities.org/donate/charitydonate.asp?ID=4081"
class="donate-btn btn-interest">DONATE</a>
Some people wanted the closing carot on a new line like this:
<a
href="http://www.nycharities.org/donate/charitydonate.asp?ID=4081"
class="donate-btn btn-interest"
>DONATE</a>
Other people wanted the closing tag at the same level as the opening tag:
<a
href="http://www.nycharities.org/donate/charitydonate.asp?ID=4081"
class="donate-btn btn-interest"
>
DONATE
</a>
I kind of hate all of them. Can anyone point to any published style guides that cover this so we can just adopt one and move on?

Answer 1

I've been wondering this as well. The only thing I could find was the guide from GoCardless, which says:
<!-- Try using line-breaks for multiple attributes, keeping the first attribute
on the tag's opening line -->
Good:
<div custom-attribute
class="something"
role="something-else"></div>
<!-- The closing tag ^^^ can stay on the same line for empty elements-->
<div custom-attribute
class="something"
role="something-else">
··Foo <!-- Otherwise nest plz -->
</div>

Answer 2

Not a definite answer, but I would like to add another suggestion: indenting the attributes twice, and the content only once.
An example:
<a
href="http://www.nycharities.org/donate/charitydonate.asp?ID=4081"
class="donate-btn btn-interest">
DONATE
</a>
For an a tag this kind of looks weird, but for longer tag-names, as are common in Angular, it looks fine:
<my-component
attribute1="val"
attribute2="val2"
attribute3="etc">
<span>Hello :)</span>
</my-component>