Make direnv description less wordy

dependency_install_steps_by_platform/Debian_9.x.md

@@ -150,9 +150,7 @@ Version: 3.5.3-1
 # Install direnv (Optional/Recommended)
 
 This tool sets and unsets environment variables as you change directories in a shell session,
-providing a convenient facility for setting up project-specific environment variables as an
-alternative to the common practice of adding project-specific configuration values to places like
-dotfiles in $HOME.
+providing a convenient facility for setting up project-specific configuration.
 
 ```
 sudo apt install direnv

dependency_install_steps_by_platform/Ubuntu_18.04.x.md

@@ -56,9 +56,7 @@ $ sudo apt install python3-venv
 # Install direnv (Optional/Recommended)
 
 This tool sets and unsets environment variables as you change directories in a shell session,
-providing a convenient facility for setting up project-specific environment variables as an
-alternative to the common practice of adding project-specific configuration values to places like
-dotfiles in $HOME.
+providing a convenient facility for setting up project-specific configuration.
 
 ```
 sudo apt install direnv

dependency_install_steps_by_platform/macOS.md

@@ -146,9 +146,7 @@ Python 3.7.2
 # Install direnv (Optional/Recommended)
 
 This tool sets and unsets environment variables as you change directories in a shell session,
-providing a convenient facility for setting up project-specific environment variables as an
-alternative to the common practice of adding project-specific configuration values to places like
-dotfiles in $HOME.
+providing a convenient facility for setting up project-specific configuration.
 
 ```
 brew install direnv