docs: remove unused documentation and scripts; update titles and metadata

Author: bybatkhuu

docs/.nav.yml

@@ -3,7 +3,6 @@ nav:
   - Getting Started: getting-started/
   - API Documentation: api-docs/
   - Development: dev/
-  - Research: research/
   # - "*"
   - Release Notes: release-notes.md
   - About: about/

docs/about/.meta.yml

@@ -1,4 +1,4 @@
 tags:
   - about
-hide:
-  - tags
+# hide:
+#   - tags

docs/api-docs/.meta.yml

@@ -1,5 +1,5 @@
 tags:
   - api-docs
   - api-reference
-hide:
-  - tags
+# hide:
+#   - tags

docs/dev/.meta.yml

@@ -1,5 +1,4 @@
 tags:
-  - dev
   - development
-hide:
-  - tags
+# hide:
+#   - tags

docs/dev/.nav.yml

@@ -2,11 +2,8 @@ nav:
   - Test: test.md
   - Build: build.md
   - Docs: docs.md
-  - Scripts: scripts/
-  - CI/CD: cicd/
   - Diagrams: diagrams.md
   - File Structure: file-structure.md
-  - Sitemap: sitemap.md
   - Related Projects: related-projects.md
   - Contributing: contributing.md
   - Roadmap: roadmap.md