Remove . from install instructions (#1468)

Make this line just a little easier to copy paste.

Author: tordans

README.md

@@ -17,15 +17,15 @@ For full documentation, visit [headlessui.dev](https://headlessui.dev).
 
 You can install the latest version by using:
 
-- `npm install @headlessui/react@latest`.
-- `npm install @headlessui/vue@latest`.
+- `npm install @headlessui/react@latest`
+- `npm install @headlessui/vue@latest`
 
 ### Installing the insiders version
 
 You can install the insiders version (which points to whatever the latest commit on the `main` branch is) by using:
 
-- `npm install @headlessui/react@insiders`.
-- `npm install @headlessui/vue@insiders`.
+- `npm install @headlessui/react@insiders`
+- `npm install @headlessui/vue@insiders`
 
 **Note:** The insiders build doesn't follow semver and therefore doesn't guarantee that the APIs will be the same once they are released.