docs: fix react sample startup guide & add needful dependency …

CONTRIBUTING.md

@@ -33,7 +33,14 @@ Build and deploy angular example
 yarn nx build angular # build the angular example
 yarn nx deploy angular # deploys angular example to gh-pages
 ```
+# Submitting a PR
+The initial comment has instructions. For your PR to be considered, you must select a template, include details, and make the appropriate selections from the checkboxes provided.
 
+1. Select the preview tab.
+2. Select the applicable template. This replaces the comment with the correct placeholder text.
+
+![Submit PR Step 1](https://github.com/near/wallet-selector/blob/main/images/submit_PR_step_1.png)
+![Submit PR Step 2](https://github.com/near/wallet-selector/blob/main/images/submit_PR_step_2.png)
 
 # Branching
 

examples/react/README.md

@@ -3,7 +3,16 @@
 This React example shows how to integrate Near Wallet Selector into your React application for easy Near wallet integration.
 
 # Usage
+Make sure your node version is 18
 
+Then perform the build:
+```bash
+yarn build:all
+```
+Need to add a separate dependency, otherwise a error `Module not found` will be reported.
+```bash
+yarn add @near-wallet-selector/modal-ui
+```
 Start the development server:
 ```bash
 yarn nx serve react