Update migrations.md

Added a line about using the command line when CLI is installed locally

docs/docs/migrations.md

@@ -8,6 +8,8 @@ In order to use the CLI you need to install the respective package:
 $ npm install --save sequelize-cli
 $ npm install --save sequelize-cli
 ```
 ```
 
 
+As with any npm package, you can use the global flag (`-g`) to install the CLI globally. If you have installed the CLI without the global flag, use `node_modules/.bin/sequelize [command]` instead of `sequelize [command]`.
+
 The CLI currently supports the following commands:
 The CLI currently supports the following commands:
 
 
 ```bash
 ```bash