Adds support for tab completion (#135)

* added support for tab completion

* minor changes in README

* updated CONTRIBUTING.md and other minor changes

* removed typo

CONTRIBUTING.md

@@ -25,7 +25,7 @@ Please proceed with a Pull Request only after you're assigned. It'd be sad if yo
     - adding better icons to [YAML files](lib/yaml/)
     - adding more flag options to the ruby gem.
 
-3. (Optional) To test whether `colorls` executable is working properly, do 
+3. (Optional) To test whether `colorls` executable is working properly, do
     ```sh
     rake install
     ```
@@ -47,3 +47,5 @@ Please proceed with a Pull Request only after you're assigned. It'd be sad if yo
     ```
 
 6. (Required for new flags) Add command to `.travis.yml` file.
+
+7. (Required for new flags) Add flags to `tab_complete.sh` file.

README.md

@@ -75,9 +75,14 @@ A Ruby script that colorizes the `ls` output with color and icons. Here are the
     rehash
     ```
 
-4. Start using `colorls` :tada:
+4. Enable tab completion for flags by entering following line to your shell configuration file (`~/.bashrc` or `~/.zshrc`) :
+    ```bash
+    source $(dirname $(gem which colorls))/tab_complete.sh
+    ```
 
-5. Have a look at [Recommended configurations](#recommended-configurations).
+5. Start using `colorls` :tada:
+
+6. Have a look at [Recommended configurations](#recommended-configurations).
 
 # Recommended configurations
 

tab_complete.sh

@@ -0,0 +1,4 @@
+_colorls_options='-1 -a -A -d -f -l -r -t -h
+--all --almost-all --dirs --files --long --report --sort-dirs --group-directories-first
+--sort-files --git-status --tree --help --sd --sf --gs'
+complete -W "${_colorls_options}" 'colorls'