chore(CHANGELOG): add an extra new line after each item in the "Breaking Changes" list

[gkalpak]

This ensures that the next item will appear on a new line and be properly
parsed as new list item (and not as the continuation of the current item),
even if the current item does not end with a newline character.
Currently, it would result is something like this:

- **item 1**: due to ...
  blah1 blah1 blah1- **item 2**: due to...
  blah2 blah2 blah2

instead of the intended:

- **item 1**: due to ...
  ...
- **item 2**: due to ...
  ...

For example, this was the case with the 1.3.0-rc.5 CHANGELOG (see the last ngAnimate breaking change).

[gkalpak]

BTW, if one puts the Closes/Fixes #XYZ lines after the BREAKING CHANGE notice, then those lines appear in the CHANGELOG (under "Breaking Changes"):

Breaking Changes

• xyzModule: due to a788e1c,

This and that breaks.

Closes #1234 Closes #5678

Do you think it would be better if:

1. either those Closes/Fixes lines where removed from the "Breaking Changes" section (since they are already mentioned above) or

2. they should be formatted as links (and each on a new line):

   Closes Made the route matcher public, allows to parse inputs from the url #1234
   Closes docs(document): so it looks better #5678

[petebacondarwin]

@gkalpak - this would benefit from a unit test in https://github.com/angular/angular.js/blob/master/changelog.spec.js

Regarding the Closes items - I think they should be stripped from the breaking changes section

[petebacondarwin]

Actually perhaps we should just be using https://github.com/ajoslin/conventional-changelog instead and provide any bug fixes to that?

[petebacondarwin]

I'm going to merge this as-is anyway since it is helpful.

[petebacondarwin]

Landed as 4474633

[rafinskipg]

You can use this grunt plugin that actually uses your changelog. https://github.com/rafinskipg/git-changelog

[rafinskipg]

I'm improving it, you can give ideas for the default options, so it would be more configurable than the actual changelog rafinskipg/git-changelog#11