Should we use `column-container` and `column-half` or `topicpage-table` and `section`?

[exe-boss]

Similarly to CSS and class confusion: "summary" vs. "seoSummary", MDN currently has topicpage-table and section, which is used on the WebExtensions landing page:

Browser Extensions

But there’s also column-container and column-half which was used on the Web/Games/Examples page until now:

https://developer.mozilla.org/docs/Games/Examples

/cc @sheppy, @jwhitlock

[sheppy (Eric Shepherd)]

The column-container and column-half classes are older ones that we are migrating away from using on newer landing pages.