Update installation instructions in README

Removed instruction to delete the *node_modules* folder after installation.

Author: thiagogq

README.md

@@ -79,7 +79,7 @@ The best way to use LibreBlog is to install it as a browser extension. That way,
 
 1. Clone this repository.
 2. Inside the repository folder, run: `npm install`.
-3. In the previous step, the necessary scripts will be copied to the *dependencies* folder, so you can delete the *node_modules* folder.
+3. In the previous step, the necessary scripts will be copied to the *dependencies* folder.
 4. Load the unpacked extension ([See how](https://developer.chrome.com/docs/extensions/get-started/tutorial/hello-world#load-unpacked)).
 
 ## How to easily test your website (and render LaTeX articles)