Merge Docusaurus site: all content under docs/, align with gregFramework split layout

- Move markdown and wiki-import tree into docs/; keep app shell at repo root
- Point docusaurus docs path to docs/; edit links to mleem97/gregWiki
- Sync and i18n scripts use gregWiki root and ../.wiki under gregFramework
- Sidebars: workspace layout from root docs ids; plugins under mods/extensions
- Fix redirects, module catalog URLs, release note paths, and wiki-import category keys
- Update repo inventory for split repos; Dockerfile for single-repo context

Made-with: Cursor

docs/mods/extensions/fmf-ui-replacement-mod.md

@@ -0,0 +1,19 @@
+---
+title: FMF.UIReplacementMod
+sidebar_label: FMF.UIReplacementMod (Legacy)
+---
+
+## Description
+
+Legacy standalone UI replacement module page kept for compatibility.
+
+## Project Status
+
+- Status: Legacy documentation entry
+- Note: No active `csproj` module was detected under `mods/` for this page.
+
+## Source
+
+- Previous mixed wiki path: `mods/standalone/fmf-ui-replacement-mod`
+
+- [Open Release Page](/wiki/releases/mods/fmf-ui-replacement-mod-release)