docs: E2E browser installation & setting up Node (#11551)

* docs: installing E2E test browsers

* docs: using required Node version

* refactor: correct use of English

CONTRIBUTING.md

@@ -92,7 +92,20 @@ To develop locally:
    - Use `openssl rand -base64 32` to generate a key and add it under `NEXTAUTH_SECRET` in the `.env` file.
    - Use `openssl rand -base64 24` to generate a key and add it under `CALENDSO_ENCRYPTION_KEY` in the `.env` file.
 
-6. Start developing and watch for code changes:
+6. Setup Node
+   If your Node version does not meet the project's requirements as instructed by the docs, "nvm" (Node Version Manager) allows using Node at the version required by the project:
+   ```sh
+   nvm use
+   ```
+   
+   You first might need to install the specific version and then use it:
+   ```sh
+   nvm install && nvm use
+   ```
+
+   You can install nvm from [here](https://github.com/nvm-sh/nvm).
+
+7. Start developing and watch for code changes:
 
    ```sh
    yarn dev
@@ -120,6 +133,15 @@ This will run and test all flows in multiple Chromium windows to verify that no
 yarn test-e2e
 ```
 
+#### Resolving issues
+##### E2E test browsers not installed
+
+Run `npx playwright install` to download test browsers and resolve the error below when running `yarn test-e2e`:
+
+```
+Executable doesn't exist at /Users/alice/Library/Caches/ms-playwright/chromium-1048/chrome-mac/Chromium.app/Contents/MacOS/Chromium
+```
+
 ## Linting
 
 To check the formatting of your code:

README.md

@@ -131,23 +131,36 @@ Here is what you need to be able to run Cal.com.
    > If you are on Windows, run the following command on `gitbash` with admin privileges: <br> > `git clone -c core.symlinks=true https://github.com/calcom/cal.com.git` <br>
    > See [docs](https://cal.com/docs/how-to-guides/how-to-troubleshoot-symbolic-link-issues-on-windows#enable-symbolic-links) for more details.
 
-1. Go to the project folder
+2. Go to the project folder
 
    ```sh
    cd cal.com
    ```
 
-1. Install packages with yarn
+3. Install packages with yarn
 
    ```sh
    yarn
    ```
 
-1. Set up your `.env` file
+4. Set up your `.env` file
    - Duplicate `.env.example` to `.env`
    - Use `openssl rand -base64 32` to generate a key and add it under `NEXTAUTH_SECRET` in the `.env` file.
    - Use `openssl rand -base64 24` to generate a key and add it under `CALENDSO_ENCRYPTION_KEY` in the `.env` file.
 
+5. Setup Node
+   If your Node version does not meet the project's requirements as instructed by the docs, "nvm" (Node Version Manager) allows using Node at the version required by the project:
+   ```sh
+   nvm use
+   ```
+   
+   You first might need to install the specific version and then use it:
+   ```sh
+   nvm install && nvm use
+   ```
+
+   You can install nvm from [here](https://github.com/nvm-sh/nvm).
+
 #### Quick start with `yarn dx`
 
 > - **Requires Docker and Docker Compose to be installed**
@@ -259,6 +272,15 @@ yarn test-e2e
 yarn playwright show-report test-results/reports/playwright-html-report
 ```
 
+#### Resolving issues
+##### E2E test browsers not installed
+
+Run `npx playwright install` to download test browsers and resolve the error below when running `yarn test-e2e`:
+
+```
+Executable doesn't exist at /Users/alice/Library/Caches/ms-playwright/chromium-1048/chrome-mac/Chromium.app/Contents/MacOS/Chromium
+```
+
 ### Upgrading from earlier versions
 
 1. Pull the current version: