docs: add mkdocs configuration and API documentation structure

- docs(mkdocs): add mkdocs.yml with material theme and plugin configuration
- docs(mkdocs): configure navigation for core, html, and pdf modules
- docs(docs): add documentation root and homepage
- docs(docs): add core contracts documentation pages
- docs(docs): add html implementation documentation pages
- docs(docs): add pdf implementation documentation pages
- docs(docs): wire mkdocstrings directives for API reference rendering

mkdocs.yml

@@ -0,0 +1,53 @@
+site_name: Aetoskia OmniRead
+site_description: Format-agnostic document reading, parsing, and scraping framework
+
+theme:
+  name: material
+  palette:
+    - scheme: slate
+      primary: deep purple
+      accent: cyan
+  font:
+    text: Inter
+    code: JetBrains Mono
+  features:
+    - navigation.tabs
+    - navigation.expand
+    - navigation.top
+    - navigation.instant
+    - content.code.copy
+    - content.code.annotate
+
+plugins:
+  - search
+  - mkdocstrings:
+      handlers:
+        python:
+          paths: ["."]
+          options:
+            docstring_style: google
+            show_source: false
+            show_signature_annotations: true
+            separate_signature: true
+            merge_init_into_class: true
+            inherited_members: true
+            annotations_path: brief
+            show_root_heading: true
+            group_by_category: true
+
+nav:
+  - Home: index.md
+
+  - Core (Contracts):
+      - Content Models: core/content.md
+      - Parsers: core/parser.md
+      - Scrapers: core/scraper.md
+
+  - HTML Implementation:
+      - HTML Parser: html/parser.md
+      - HTML Scraper: html/scraper.md
+
+  - PDF Implementation:
+      - PDF Client: pdf/client.md
+      - PDF Parser: pdf/parser.md
+      - PDF Scraper: pdf/scraper.md