chore(docs/readme): fix checkboxes

Author: hasundue

README.md

@@ -33,10 +33,10 @@ relays, oriented to web standards and edge environments.
       protocol
 - [x] [NIP-02](https://github.com/nostr-protocol/nips/blob/master/02.md):
       Contact list
-- [] [NIP-7](https://github.com/nostr-protocol/nips/blob/master/7.md):
-  `window.nostr` capability for web browsers
-- [] [NIP-42](https://github.com/nostr-protocol/nips/blob/master/42.md): Client
-  authentication
+- [ ] [NIP-7](https://github.com/nostr-protocol/nips/blob/master/7.md):
+      `window.nostr` capability for web browsers
+- [ ] [NIP-42](https://github.com/nostr-protocol/nips/blob/master/42.md): Client
+      authentication
 
 ## References