Add missing files

Fixes #125.
Fix typo in `showModalDialog` demo

Hat tip: @zcorpan.
Avoid minifying demo HTML files

Closes #129.
Markdown and missed resources
Fix broken jQuery plugin in ‘Custom HTML5 video player’ article

Ref. #130.
Markdown and missed resources
Merge branch 'master' of github.com:operasoftware/devopera
Better styles for lists
Extra classes for figures
Tags
Pade.id shorthands for image paths
Page.id shorthand; Extra classes for figures
Markdown and resources for “Microformat Encoding and Visualization” article
Markdown and resources for “CSS Text Shadows and Background Sizing” article
Merge branch 'master' of github.com:operasoftware/devopera
minor spelling tweaks