add md files explicitely

Author: silverwind

Makefile

@@ -146,7 +146,7 @@ WEB_DIRS := web_src/js web_src/css
 
 ESLINT_FILES := web_src/js tools *.js tests/e2e
 STYLELINT_FILES := web_src/css web_src/js/components/*.vue
-SPELLCHECK_FILES := $(GO_DIRS) $(WEB_DIRS) docs/content templates options/locale/locale_en-US.ini .github *.go *.js *.md *.yml *.yaml *.toml
+SPELLCHECK_FILES := $(GO_DIRS) $(WEB_DIRS) docs/content templates options/locale/locale_en-US.ini .github *.go *.js *.yml *.yaml *.toml CODE_OF_CONDUCT.md CONTRIBUTING.md README.md README_ZH.md SECURITY.md
 EDITORCONFIG_FILES := templates .github/workflows options/locale/locale_en-US.ini
 
 GO_SOURCES := $(wildcard *.go)