Import upstream changes (441baca292f7e7df2c2a2a2453b027b3ade0a8bc)

Author: lit-robot

README.md

@@ -95,7 +95,7 @@ npm run lint
 
 [Prettier](https://prettier.io/) is used for code formatting. It has been pre-configured according to the Lit's style. You can change this in `.prettierrc.json`.
 
-Prettier has not been configured to run when committing files, but this can be added with Husky and and `pretty-quick`. See the [prettier.io](https://prettier.io/) site for instructions.
+Prettier has not been configured to run when committing files, but this can be added with Husky and `pretty-quick`. See the [prettier.io](https://prettier.io/) site for instructions.
 
 ## Static Site