Mkdocs-rss-plugin

Fixed

* Fix 95: introduced logic did not handle case where categories meta keys are not defined

----

Added

* new option to include [RSS `<category>` item element](https://www.w3schools.com/xml/rss_tag_category_item.asp) using page metadata (YAML frontmatter). It's customizable to get custom meta keys for keywords/tags. PR [#4](https://github.com/Guts/mkdocs-rss-plugin/pull/4)

----

Added

* option to get the full page content into thread. Contributed by [liang2kl](https://github.com/liang2kl) with [PR 88](https://github.com/Guts/mkdocs-rss-plugin/pull/88). See the [related documentation section](https://guts.github.io/mkdocs-rss-plugin/configuration/#item-description-length).

Changed

* documentation on ReadTheDocs has been removed to reduce confusion and dependencies. [PR 89](https://github.com/Guts/mkdocs-rss-plugin/pull/89).

----

Changed

* bump MkDocs maximal version

Fixed

* improve DockerFile used to test, fixing it after Material removed some dependencies

----

Fixed

* remove a print statement

----

Added

* add option to handle the [RSS item comments element](https://www.w3schools.com/XML/rss_tag_comments.asp) through item URL path (see [documentation](https://guts.github.io/mkdocs-rss-plugin/configuration/#item-comments-path))

Changed

* ignore `urllib.error.URLError` exception to avoid build crashes typically when network is offline

----