chore: add markdown lint check to default lint command

CONTRIBUTING.md

@@ -257,13 +257,21 @@ cd packages/opentelemetry-module-name
 npm run lint:fix
 ```
 
-Similarly, Markdown files (such as README.md files) can be linted:
+The default lint command will check majority of files, including Markdown files (such as README.md files), but you
+also have the option to check just the Markdown files with:
 
 ```sh
 npm run lint:markdown
 npm run lint:markdown:fix # can automatically fix some Markdown rules
 ```
 
+The default command doesn't check the examples folder. To lint just the examples, use the script:
+
+```sh
+npm run lint:examples
+npm run lint:examples:fix # can automatically fix some errors
+```
+
 ### Generating docs
 
 We use [typedoc](https://www.npmjs.com/package/typedoc) to generate the api documentation.

package.json

@@ -21,9 +21,9 @@
     "docs": "typedoc --readme none && touch docs/.nojekyll",
     "docs-deploy": "gh-pages --dotfiles --dist docs",
     "docs:test": "linkinator docs --silent --retry && linkinator doc/*.md --skip http://localhost:3000 --skip http://localhost:9464 --silent --retry",
-    "lint": "lerna run lint",
+    "lint": "lerna run lint && markdownlint-cli2 $(git ls-files '*.md')",
     "lint:changed": "lerna run --concurrency 1 --stream lint --since HEAD --exclude-dependents",
-    "lint:fix": "lerna run lint:fix",
+    "lint:fix": "lerna run lint:fix && markdownlint-cli2 --fix $(git ls-files '*.md')",
     "lint:fix:changed": "lerna run --concurrency 1 --stream lint:fix --since HEAD --exclude-dependents",
     "lint:examples": "eslint --no-error-on-unmatched-pattern ./examples/**/*.js",
     "lint:examples:fix": "eslint --no-error-on-unmatched-pattern ./examples/**/*.js --fix",