Document that non-spec changes should get an 'internal' changelog entry (#1342)

CONTRIBUTING.rst

@@ -76,8 +76,12 @@ All API specifications require a changelog entry. Adding to the changelog can on
 be done after you've opened your pull request, so be sure to do that first.
 
 The changelog is managed by `Towncrier <https://github.com/twisted/towncrier>`_ in the
-form of "news fragments". The news fragments for the client-server API are stored
-under ``changelogs/client_server/newsfragments``.
+form of "news fragments". Depending on which API you changed, an entry should be added to
+each relevant API's ``newsfragments`` directory. A directory exists for each API under
+``changelogs/``. For instance, news fragments for the client-server API are stored
+under ``changelogs/client_server/newsfragments``. Any changes to the repository that do
+not affect the spec content itself, such as changes to the build script, formatting, CSS,
+etc. should be documented under ``changelogs/internal/newsfragments``.
 
 To create a changelog entry, create a file named in the format ``prNumber.type`` in
 the ``newsfragments`` directory. The ``type`` can be one of the following:
@@ -99,9 +103,6 @@ All news fragments must have a brief summary explaining the change in the
 contents of the file. The summary must end in a full stop to be in line with
 the style guide and formatting must be done using Markdown.
 
-Changes that do not change the spec, such as changes to the build script, formatting,
-CSS, etc should not get a news fragment.
-
 Sign off
 --------
 

changelogs/internal/newsfragments/1342.clarification

@@ -0,0 +1 @@
+Update CONTRIBUTING.md to mention that non-content changes to this repo should have an "internal" changelog entry.