Migrate to gitbook (#357)

This PR facilities the migration from the old Writerside documentation
platform to Gitbook.

## motivation

Gitbook supports serving multiple versions of the documentation, e.g.
v1.12.1, v1.13.0, and master.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -53,5 +53,5 @@ YOUR CONFIG HERE
 ```
 
  - [ ] I understand, that without logs and/or screenshots and a detailed description of the problem, it is very hard to fix bugs.
- - [ ] I have checked the [documentation](https://maxdorninger.github.io/MediaManager/introduction.html) for help.
+ - [ ] I have checked the [documentation](https://maximilian-dorninger.gitbook.io/mediamanager) for help.
  - [ ] I have searched the [issues](https://github.com/maxdorninger/MediaManager/issues) for similar issues and found none.

.github/workflows/build-docs.yml

@@ -1,139 +0,0 @@
-name: Build documentation
-
-on:
-  push:
-    branches: [ "master" ]
-    paths:
-      - 'Writerside/**'
-      - '.github/workflows/build-docs.yml'
-  workflow_dispatch:
-
-permissions:
-  contents: read
-  id-token: write
-  pages: write
-
-env:
-  INSTANCE: 'Writerside/mm'
-  DOCKER_VERSION: '2025.04.8412'
-  ALGOLIA_APP_NAME: '5SXJTW5J6S'
-  ALGOLIA_INDEX_NAME: 'MediaManagerDocs'
-  CONFIG_JSON_PRODUCT: 'MM'
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    outputs:
-      algolia_artifact: ${{ steps.define-ids.outputs.algolia_artifact }}
-      artifact: ${{ steps.define-ids.outputs.artifact }}
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-
-      - name: Define instance id and artifacts
-        id: define-ids
-        run: |
-          INSTANCE=${INSTANCE#*/}
-          INSTANCE_ID_UPPER=$(echo "$INSTANCE" | tr '[:lower:]' '[:upper:]')
-          ARTIFACT="webHelp${INSTANCE_ID_UPPER}2-all.zip"
-          ALGOLIA_ARTIFACT="algolia-indexes-${INSTANCE_ID_UPPER}.zip"
-
-          # Print the values
-          echo "INSTANCE_ID_UPPER: $INSTANCE_ID_UPPER"
-          echo "ARTIFACT: $ARTIFACT"
-          echo "ALGOLIA_ARTIFACT: $ALGOLIA_ARTIFACT"
-
-          # Set the environment variables and outputs
-          echo "INSTANCE_ID_UPPER=$INSTANCE_ID_UPPER" >> $GITHUB_ENV
-          echo "ARTIFACT=$ARTIFACT" >> $GITHUB_ENV
-          echo "ALGOLIA_ARTIFACT=$ALGOLIA_ARTIFACT" >> $GITHUB_ENV
-          echo "artifact=$ARTIFACT" >> $GITHUB_OUTPUT
-          echo "algolia_artifact=$ALGOLIA_ARTIFACT" >> $GITHUB_OUTPUT
-
-      - name: Build docs using Writerside Docker builder
-        uses: JetBrains/writerside-github-action@v4
-        with:
-          instance: ${{ env.INSTANCE }}
-          docker-version: ${{ env.DOCKER_VERSION }}
-
-      - name: Save artifact with build results
-        uses: actions/upload-artifact@v4
-        with:
-          name: docs
-          path: |
-            artifacts/${{ steps.define-ids.outputs.artifact }}
-            artifacts/report.json
-            artifacts/${{ steps.define-ids.outputs.algolia_artifact }}
-          retention-days: 7
-  test:
-    needs: build
-    runs-on: ubuntu-latest
-    steps:
-      - name: Download artifacts
-        uses: actions/download-artifact@v4
-        with:
-          name: docs
-          path: artifacts
-
-      - name: Test documentation
-        uses: JetBrains/writerside-checker-action@v1
-        with:
-          instance: ${{ env.INSTANCE }}
-  deploy:
-    environment:
-      name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}
-    needs: [ build, test ]
-    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository
-    runs-on: ubuntu-latest
-    steps:
-      - name: Download artifacts
-        uses: actions/download-artifact@v4
-        with:
-          name: docs
-          path: artifacts
-
-      - name: Unzip artifact
-        run: unzip -O UTF-8 -qq "artifacts/${{ needs.build.outputs.artifact }}" -d dir
-
-      - name: Setup Pages
-        uses: actions/configure-pages@v4
-
-      - name: Package and upload Pages artifact
-        uses: actions/upload-pages-artifact@v3
-        with:
-          path: dir
-
-      - name: Deploy to GitHub Pages
-        id: deployment
-        uses: actions/deploy-pages@v4
-  publish-indexes:
-    needs: [ build, test, deploy ]
-    runs-on: ubuntu-latest
-    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository
-    container:
-      image: registry.jetbrains.team/p/writerside/builder/algolia-publisher:2.0.32-3
-    steps:
-      - name: Download artifact
-        uses: actions/download-artifact@v4
-        with:
-          name: docs
-          path: artifacts
-      - name: Unzip Algolia artifact
-        run: unzip -O UTF-8 -qq "artifacts/${{ needs.build.outputs.algolia_artifact }}" -d algolia-indexes
-      - name: Update Algolia Index
-        run: |
-          if [ -z "${{ secrets.ALGOLIA_KEY }}" ]; then
-            echo "ALGOLIA_KEY secret is not set in GitHub Secrets"
-            exit 1
-          else
-            env "algolia-key=${{ secrets.ALGOLIA_KEY }}" java -jar /opt/builder/help-publication-agent.jar \
-            update-index \
-            --application-name ${{ env.ALGOLIA_APP_NAME }} \
-            --index-name ${{ env.ALGOLIA_INDEX_NAME }} \
-            --product ${{ env.CONFIG_JSON_PRODUCT }} \
-            --index-directory algolia-indexes/ \
-            2>&1 | tee algolia-update-index-log.txt
-          fi