Update README.md

Author: viniciussanchez

README.md

@@ -8,7 +8,7 @@
 ## ⚙️ Installation
 Installation is done using the [`boss install`](https://github.com/HashLoad/boss) command:
 ``` sh
-$ boss install horse-basic-auth
+boss install horse-basic-auth
 ```
 If you choose to install manually, simply add the following folders to your project, in *Project > Options > Resource Compiler > Directories and Conditionals > Include file search path*
 ```