fix typo and some seds for <empty> (#15)

# Before:

![Screen Shot 2023-05-26 at 15.48.12](/attachments/09d9a965-1587-40c9-b81b-e8416ac0c226)![Screen Shot 2023-05-26 at 15.48.17](/attachments/8beda8a1-5c49-4c87-95e7-e4aa95e56ec9)![Screen Shot 2023-05-26 at 15.48.57](/attachments/21dad81e-eed1-4280-bbb4-eeda039bec41)![Screen Shot 2023-05-26 at 16.14.44](/attachments/07a3148a-52ea-43bb-8e07-c0d8f31d1c24)

# After:

![Screen Shot 2023-05-26 at 16.02.38](/attachments/24239f32-6e9a-487c-8532-b6bd22ca6a50)(/attachments/85c184f3-58ca-4616-bb9d-9afacbc59290)![Screen Shot 2023-05-26 at 16.03.02](/attachments/4952880a-3254-4139-8943-ff37a9797bd7)![Screen Shot 2023-05-26 at 16.05.03](/attachments/ef77be92-2c60-4962-8b0a-efeed63a663b)![Screen Shot 2023-05-26 at 16.15.22](/attachments/22ea1d0b-2838-488d-92c7-e2db8e53ebae)

Reviewed-on: https://gitea.com/gitea/gitea-docusaurus/pulls/15
Reviewed-by: Lunny Xiao <[email protected]>
Co-authored-by: HesterG <[email protected]>
Co-committed-by: HesterG <[email protected]>

.gitea/workflows/test.yaml

@@ -0,0 +1,32 @@
+name: checks
+
+on:
+  - pull_request
+
+jobs:
+  build-docs:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: https://github.com/actions/setup-node@v3
+        with:
+          node-version: 16
+      - name: install necessary tools
+        run: |
+          apt update -y && apt install -y rsync python python3-pip
+          pip install awscli
+      - name: prepare nightly docs
+        run: |
+          make prepare-latest
+          make prepare-latest-zh-cn
+      - name: prepare 1.19 docs
+        run: |
+          make prepare\#19
+          make prepare-zh-cn\#19
+      - name: cleanup before build
+        run: |
+          rm static/_*
+      - name: build site
+        run: |
+          npm ci
+          npm run build