Fix typos (#3646)

docs/plugins/publishing.md

@@ -1,16 +1,16 @@
 ---
 id: publishing
 title: Publishing
-description: Documentation on Publishing NPM packages
+description: Documentation on Publishing npm packages
 ---
 
-## NPM
+## npm
 
-NPM packages are published through CI/CD in the
+npm packages are published through CI/CD in the
 [.github/workflows/master.yml](https://github.com/backstage/backstage/blob/master/.github/workflows/master.yml)
 workflow. Every commit that is merged to master will be checked for new versions
 of all public packages, and any new versions will automatically be published to
-NPM.
+npm.
 
 ### Creating a new release