Revert more documentation changes (formerly due to hydration issues b…

…ut resolved by MarkBind#1548)

docs/devGuide/design/architecture.md

@@ -25,7 +25,6 @@ The 3 key classes representing different types of content are as follows:
 1. `Layout` — a single layout file, as contained in the `_markbind/layouts` folder, collectively managed by `LayoutManager`.
 
     <box type="tip" seamless>Note that `Layout` instances do not generate any output files directly, but rather, they store intermediate processing results to be used in a `Page`.</box>
-
 1. `External` — source files referenced in a `Page`, `Layout` or even another `External` that result in a <tooltip content="hence the class naming `External`">**separate**</tooltip> output file. These output files are loaded dynamically and on-demand in the browser. These instances are managed by a single `ExternalManager` instance.
 
 <box type="info" seamless>