chore: update GitHub Actions workflows and unify doc generation (#9)

* Create main.yml

* chore: Rename GitHub workflow file and update .NET setup

Moved .github/workflows/main.yml to .github/workflows/generate-docs.yml and added .NET 8 setup step for documentation generation.

* chore: Update docs generation workflow and standardize README filenames

- Update .NET version from 8 to 9 in GitHub Actions workflow
- Change docfx action from CaseyHofland/docfx-unitypackage to Bli-AIk/docfx-unitypackage
- Rename readme.md and its meta file to uppercase README.md for consistency

* chore: Update GitHub Actions workflow to use fixed version of docfx-unitypackage action

Author: Bli-AIk

.github/workflows/generate-docs.yml

@@ -0,0 +1,37 @@
+name: docfx-unitypackage
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+
+jobs:
+  build-and-deploy:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: true
+
+      - name: Setup .NET 9
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '9.0'
+
+
+      - name: Build
+        uses: Bli-AIk/docfx-unitypackage@v1.0.0
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Deploy
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_branch: gh-pages
+          publish_dir: _site