blurb: inconsistent spacing in changelog.html

[ned-deily]

The rendered changelog.html files produced with blurb and make html have inconsistent spacing between items. Usually, the first changelog topic section (e.g. Security) starts with no blank lines between items but occasionally some subsequent sections will render with a blank link between items; this seems to be often true for the Library section, but not always. This is visible across the blurbified 3.x branches; here's an example with the stable 3.5 docs:

Library section has blank line separator:
https://docs.python.org/3.5/whatsnew/changelog.html#id5

Library section has no blank separators:
https://docs.python.org/3.5/whatsnew/changelog.html#id11

[larryhastings]

blurb generates identical formatting in the RST file. It looks to me like the RST to HTML converter is the one that's being inconsistent, and I have no idea why. But this isn't blurb's doing.

[ned-deily]

But it's easier to blame blurb! (Thanks for investigating.)

[larryhastings]

Note also that the changelog displayed this behavior long before blurb was created. For example, here's the changelog from 3.4.4, released in 2015.

With blank line separator:

https://docs.python.org/release/3.4.4/whatsnew/changelog.html#id152

Without blank line separator:

https://docs.python.org/release/3.4.4/whatsnew/changelog.html#id2

[ned-deily]

I've opened a doc bug: https://bugs.python.org/issue32523