Publish 0.6.0

• Publish now requires Swift version 5.2.
• If a Markdown file doesn’t contain a title (H1), that file’s name is now used as a fallback for the corresponding item’s title (by @bensyverson).
• Items can now be filtered out of a given RSS feed by passing an itemPredicate when using the generateRSSFeed publishing step.
• An item’s body can now be prefixed and suffixed when it appears within an RSS feed.
• Items can now be removed from a section (by @peteschaffner).
• When writing a custom deployment method, you can now pass an outputFolderPath when creating a deployment folder for it, to have the website’s output copied into a nested folder (by @BaGuIO and @john-mueller).