feat: add asciidoc editor module (#5954)

* feat: add asciidoc editor module

* fix storage file extension for asciidoc pages

* fix: asciidoc editor + rendering improvements

* fix: description list css improvements

Co-authored-by: NGPixel <github@ngpixel.com>

server/helpers/page.js

@@ -10,6 +10,7 @@ const unsafeCharsRegex = /[\x00-\x1f\x80-\x9f\\"|<>:*?]/
 
 const contentToExt = {
   markdown: 'md',
+  asciidoc: 'adoc',
   html: 'html'
 }
 const extToContent = _.invert(contentToExt)