Knowledge base: /docs/<title> permalinks, search, categories, count, better PDF

Articles get their own address (shareable, back/forward work); the list is
searchable by title and text, shows the article count, and is grouped into
Applications and Troubleshooting & Guides via a hidden category line set
from the editor. PDF export lays out at page width with page breaks, a title
block and page numbers; Print uses the browser's vector print. Inline code
is a pill that glows blue on hover, blockquotes no longer squeeze, and
GitHub-style [!NOTE] alerts render. [[Badge]] syntax inside code spans is
left alone.

Documentation/Create Bootable USB.md

@@ -1,3 +1,4 @@
+<!-- category: Troubleshooting & Guides -->
 [[Gray:Reference]]
 
 # Create a Bootable Imaging USB