[core] Fix npm reference

See https://css-tricks.com/start-sentence-npm/ for why

CHANGELOG.md

@@ -7123,7 +7123,7 @@ You can find more information about the new api, including how to set those tran
 - [core] Add link to the security page on the `README` (#6073) @oliviertassinari
 - [core] Fix scroll restoration in the docs (#5938) @oliviertassinari
 - [core] Remove the Storybook (#6099) @flaviendelangle
-- [core] Tag release as `next` in NPM (#6256) @m4theushw
+- [core] Tag release as `next` in npm (#6256) @m4theushw
 - [core] Update monorepo (#6180) @flaviendelangle
 - [core] Use the `next` branch for Prettier (#6097) @flaviendelangle
 - [core] Use the official repository for `@mui/monorepo` instead of a fork (#6189) @oliviertassinari

scripts/README.md

@@ -2,7 +2,7 @@
 
 ## Release
 
-> Tip: For people who are doing the release for the first time, make sure you sign in to NPM from the command line using security-key flow as well as have two-factor authentication enabled.
+> Tip: For people who are doing the release for the first time, make sure you sign in to npm from the command line using security-key flow as well as have two-factor authentication enabled.
 > You can follow [this guide](https://docs.npmjs.com/accessing-npm-using-2fa) for more information on how to set it up.
 
 > Tip: You can copy raw markdown checklist below to the release Pull Request and follow it step by step marking completed items.