enrich CI: add linters for Markdown, YAML, Python (PEP8)

Author: kolomenkin

.config/.flake8

@@ -0,0 +1,10 @@
+# flake8 checks for PEP-8 compliance
+# https://flake8.pycqa.org/en/latest/user/configuration.html
+
+[flake8]
+
+max-line-length = 120
+
+exclude =
+    .git,
+    .temp

.config/.markdownlint.yaml

@@ -0,0 +1,25 @@
+# Manual for `.markdownlint.yaml` config:
+# https://github.com/DavidAnson/markdownlint#optionsconfig
+# Config file JSON schema:
+# https://github.com/DavidAnson/markdownlint/blob/main/schema/markdownlint-config-schema.json
+---
+default: true
+
+# Trailing spaces
+MD009:
+  br_spaces: 2
+
+# Line length
+MD013:
+  line_length: 140
+  code_blocks: false
+  tables: false
+
+# Multiple headers with same content
+MD024:
+  siblings_only: true
+
+# Inline HTML
+MD033:
+  allowed_elements:
+    - br

.config/.yamllint.yaml

@@ -0,0 +1,21 @@
+# Manual for `.yamllint.yaml` config:
+# https://yamllint.readthedocs.io/en/stable/configuration.html
+---
+extends: default
+
+yaml-files:
+  - '*.yaml'
+  - '*.yml'
+  - '.yamllint'
+
+rules:
+  line-length:
+    max: 120
+    level: warning
+  brackets:
+    min-spaces-inside: 1
+    max-spaces-inside: 1
+  comments:
+    min-spaces-from-content: 1
+  new-lines:
+    type: unix

.github/workflows/build_cmake.yml

@@ -64,6 +64,24 @@ jobs:
     steps:
       - uses: actions/checkout@v2
 
+      - name: Check Markdown syntax (docker)
+        if: runner.os == 'Linux'
+        shell: sh
+        run: |
+          make -- check-md
+
+      - name: Check YAML syntax (docker)
+        if: runner.os == 'Linux'
+        shell: sh
+        run: |
+          make -- check-yaml
+
+      - name: Check Python syntax (PEP8) (docker)
+        if: runner.os == 'Linux'
+        shell: sh
+        run: |
+          make -- check-pep8
+
       - name: Set up Python ${{ env.PYTHON_VERSION }}
         uses: actions/setup-python@v3
         with:

Makefile

@@ -0,0 +1,40 @@
+# =================================
+CODE_DIR_ROOT = ./
+
+FLAKE8_CONFIG       = ./.config/.flake8
+MARKDOWNLINT_CONFIG = ./.config/.markdownlint.yaml
+YAMLLINT_CONFIG     = ./.config/.yamllint.yaml
+
+# =================================
+
+check-all: check-md check-yaml check-pep8
+
+# =================================
+
+check-md:
+# Using two slashes at the beginning of the paths for Windows bash shell
+	docker run --rm --tty --network=none --volume="${CURDIR}:/markdown:ro" \
+		--workdir=//markdown/ \
+		06kellyjac/markdownlint-cli:0.27.1-alpine \
+            --config=${MARKDOWNLINT_CONFIG} \
+            --ignore=./dependency/CrowCpp/README.md \
+			-- ./
+
+check-yaml:
+# Using two slashes at the beginning of the paths for Windows bash shell
+	docker run --rm --tty --network=none --volume="$(CURDIR):/data:ro" \
+		--workdir=//data/ \
+		cytopia/yamllint:1.26-0.9 \
+            -c=${YAMLLINT_CONFIG} \
+			--strict \
+			-- ./
+
+check-pep8:
+# Using two slashes at the beginning of the paths for Windows bash shell
+	docker run --rm --tty --network=none --volume="${CURDIR}:/apps:ro" \
+		--workdir=//apps/ \
+		alpine/flake8:4.0.1 \
+			--config=${FLAKE8_CONFIG} \
+			-- ${CODE_DIR_ROOT}
+
+# =================================