Add pandoc for PDF creation and GitHub Actions for auto-generation

.github/workflows/main.yml

@@ -0,0 +1,46 @@
+---
+name: Generate PDF using Pandoc
+
+# Controls when the workflow will run
+on:
+  # Triggers the workflow on push or pull request events but only for the master branch
+  push:
+    branches: [ master ]
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+  # This workflow contains a single job called "create_pdf"
+  create_pdf:
+    # The type of runner that the job will run on
+    runs-on: ubuntu-20.04
+
+    # Pandoc Docker image v2.17.0.1
+    container:
+      image: pandoc/latex:2.17.0.1
+
+    # Steps represent a sequence of tasks that will be executed as part of the job
+    steps:
+      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
+      - uses: actions/checkout@v2
+
+      # Run the PDF creation script in the container
+      - uses: docker://pandoc/latex:2.17.0.1
+        with:
+          entrypoint: './pandoc-docker.sh'
+
+      # Create an output with the shortened version of the commit SHA
+      - id: short_sha
+        env:
+          GITHUB_SHA: ${{ github.sha }}
+        run: echo "::set-output name=short_sha::$(echo ${GITHUB_SHA::7})"
+
+      # Create a release with the PDFs as assets and the shortened SHA as the tag name
+      - uses: softprops/action-gh-release@v1
+        with:
+          tag_name: v${{ steps.short_sha.outputs.short_sha }}
+          draft: false
+          files: |
+            *.pdf

.gitignore

@@ -1,5 +1,6 @@
 # Byte-compiled / optimized / DLL files
 *.epub
+*.pdf
 __pycache__/
 *.py[cod]
 
@@ -61,4 +62,4 @@ target/
 scratch/
 
 # IPython Notebook templates
-template.ipynb
+template.ipynb

README-zh-Hans.md

@@ -1193,7 +1193,7 @@ def get_user(self, user_id):
 ##### 缓存的缺点：
 
 - 请求的数据如果不在缓存中就需要经过三个步骤来获取数据，这会导致明显的延迟。
-- 如果数据库中的数据更新了会导致缓存中的数据过时。这个问题需要通过设置 TTL 强制更新缓存或者直写模式来缓解这种情况。
+- 如果数据库中的数据更新了会导致缓存中的数据过时。这个问题需要通过设置 TTL 强制更新缓存或者直写模式来缓解这种情况。
 - 当一个节点出现故障的时候，它将会被一个新的节点替代，这增加了延迟的时间。
 
 #### 直写模式