Swap emoji and unicode glyphs for Tabler components so icons inherit
currentColor and font-size and render consistently across platforms.
- add src/components/doc-icons.ts to resolve doc-entry frontmatter icon
keys to components; frontmatter now stores semantic keys
- replace the align-*.png assets with TbOutlineAlign* icons
- render RevealManager action SVGs as components instead of injected
innerHTML strings
- carry completion icons via an optional CompletionItem.icon field
hypercross