Add init command to docs

Author: alexcanessa

README.md

@@ -119,6 +119,14 @@ Then add this line to  `~/.bash_profile` (or `~/.zshrc`):
 export GREN_GITHUB_TOKEN=your_token_here
 ```
 
+#### Init
+
+If you need help to create the configuration file, you can run the following command and follow the instructions
+
+```
+gren init
+```
+
 ## Basic Usage
 
 `gren` gets the repo information directly from the folder where `git` is initialised.

docs/options.md

@@ -36,6 +36,12 @@ The options are the same on specified above but in camelCase *e.g*:
 }
 ```
 
+If you need help to create the configuration file, you can run the following command and follow the instructions
+
+```
+gren init
+```
+
 ### Group By
 
 Via the configuration file you can have more complex grouping, using labels in a more creative way.