Merge pull request #471 from mcarmonaa/fix/docs-oniguruma-installation

docs: fix how to install oniguruma on linux

Author: ajnavarro

docs/using-gitbase/getting-started.md

@@ -64,8 +64,13 @@ brew install oniguruma
 
 Linux:
 
+- Debian-based distros:
 ```
-sudo apt-get install libonig2
+sudo apt-get install libonig2 libonig-dev
+```
+- Arch linux:
+```
+pacman -S oniguruma
 ```
 
 Then build gitbase like this: