Remove quotes from installation instructions (#19)

Removed the quotes from around `~/.dir_colors` in the installation
instructions. Before the shell specific tilde character was not resolved
via variable expansion but used as literal character instead. 

Co-authored-by: Arctic Ice Studio <development@arcticicestudio.com>
Co-authored-by: Sven Greb <development@svengreb.de>

Fixes GH-15
Fixes GH-18
Related to GH-11

README.md

@@ -27,15 +27,15 @@ For more details see the [official installation & activation guide][nord-docs-ho
 To always use the latest development state of Nord dircolors, [clone the repository][repo] and create a [symbolic link][wiki-symlink] of the `src/dir_colors` file to `~/.dir_colors` in your [home directory][wiki-home_dir] afterwards:
 
 ```sh
-ln -sr "$PWD/src/dir_colors" "~/.dir_colors"
+ln -sr "$PWD/src/dir_colors" ~/.dir_colors
 ```
 
 #### Activation
 
 To activate and use Nord dircolors as your default color theme for all sessions, load the theme with `dircolors` by adding the following snippet to the configuration file of your shell (`~/.bashrc`, `~/.zshrc`, …):
 
 ```sh
-test -r "~/.dir_colors" && eval $(dircolors ~/.dir_colors)
+test -r ~/.dir_colors && eval $(dircolors ~/.dir_colors)
 ```
 
 <p align="center"><img src="https://raw.githubusercontent.com/arcticicestudio/nord-docs/develop/assets/images/ports/dircolors/installation-shell-rc.png"/></p>