make links valid (codesandbox#1575)

otherwise these links are eg 404 at https://codesandbox.io/docs/embedding

Author: martenson

packages/homepage/content/docs/2-embedding.md

@@ -9,7 +9,7 @@ description: "It's possible to embed a sandbox on Medium and other websites."
 CodeSandbox has a separate application for the embed. This application is
 specifically built to be as small as possible. If you replace `s` in the URL of
 a sandbox to `embed` you have the embed version of the sandbox. Example:
-https://codesandbox.io/**s**/new => https://codesandbox.io/**embed**/new. Notice
+https://codesandbox.io/s/new => https://codesandbox.io/embed/new. Notice
 that the embed doesn't have all features of the full editor.
 
 ## Generate a URL