v2.2.0

Added

• template files are loaded once at the start and then cached with their front-matter (see issue 87)
• .njk is interpreted as a nunjuck template (see issue 75)
• error when integer in graphql query variable can't be parsed (see issue 84)

Fixed

• html-convertor can't convert a template using a layout that in turn extends another layout
• class RdfConverter does not obey Convertor interface (see issue 58)
• Fix memory leak (see issue 83)

Changed

• Update Comunica deps (see issue 98)