Update installation instructions for the extension CLI in getting-started.md

Author: estruyf

content/docs/getting-started.md

@@ -26,7 +26,7 @@ You can get the extension via:
 <!-- markdownlint-disable MD033 MD013 MD028 -->
 
 - The VS Code marketplace: [VS Code Marketplace - Front Matter][01].
-- The extension CLI: `ext install eliostruyf.vscode-front-matter`
+- The extension CLI: `code --install-extension eliostruyf.vscode-front-matter`
 - Or by clicking on the following link: <a href="" title="open extension in VS Code" data-vscode="vscode:extension/eliostruyf.vscode-front-matter">open extension in VS Code</a>
 
 ### Beta version
@@ -35,7 +35,7 @@ If you have the courage to test out the beta features, we made available a beta
 can install this via:
 
 - The VS Code marketplace: [VS Code Marketplace - Front Matter BETA][02].
-- The extension CLI: `ext install eliostruyf.vscode-front-matter-beta`
+- The extension CLI: `code --install-extension eliostruyf.vscode-front-matter-beta`
 - Or by clicking on the following link: <a href="" title="open extension in VS Code" data-vscode="vscode:extension/eliostruyf.vscode-front-matter-beta">open extension in VS Code</a>
 
 > **Info**: The BETA docs can be found on [beta.frontmatter.codes][03].