Support article display format editing (font, font size, etc.)

[nramos0]

Story

• As a normal user, I can select a preferred font size when reading articles, so that I can better tune the reader to my own preferences.
• As a normal user, I can select a preferred font when reading articles, so that I can better tune the reader to my own preferences.
• As a normal user, I can select a preferred text align format when reading articles, so that I can better tune the reader to my own preferences.