Update distribution_linux.md

Clarifies installation instructions a bit.

doc/distribution_linux.md

@@ -14,36 +14,37 @@ The steps are described in [Linux manual installation guide](./installation.md)
 
 
 ## Installing the packages:
-- Register the server's public key :  
+- Register the server's public key:  
 `sudo apt-key adv --keyserver keys.gnupg.net --recv-key C8B3A55A6F3EFCDE || sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-key C8B3A55A6F3EFCDE`  
 In case the public key still cannot be retrieved, check and specify proxy settings: `export http_proxy="http://<proxy>:<port>"`  
 , and rerun the command. See additional methods in the following [link](https://unix.stackexchange.com/questions/361213/unable-to-add-gpg-key-with-apt-key-behind-a-proxy).  
 
-- Add the server to the list of repositories :  
+- Add the server to the list of repositories:  
   Ubuntu 16 LTS:  
 `sudo add-apt-repository "deb http://realsense-hw-public.s3.amazonaws.com/Debian/apt-repo xenial main" -u`  
   Ubuntu 18 LTS:  
 `sudo add-apt-repository "deb http://realsense-hw-public.s3.amazonaws.com/Debian/apt-repo bionic main" -u`
 
- When upgrading, remove the old records:  
-  - `sudo rm -f /etc/apt/sources.list.d/realsense-public.list`.  
-  - `sudo apt-get update`.  
-
-- In order to run demos install:  
+- Install the libraries (see section below if upgrading packages):  
   `sudo apt-get install librealsense2-dkms`  
   `sudo apt-get install librealsense2-utils`  
   The above two lines will deploy librealsense2 udev rules, build and activate kernel modules, runtime library and executable demos and tools.  
 
- Reconnect the Intel RealSense depth camera and run: `realsense-viewer` to verify the installation.
-
-- Developers shall install additional packages:  
+- Optionally install the developer and debug packages:  
   `sudo apt-get install librealsense2-dev`  
   `sudo apt-get install librealsense2-dbg`  
   With `dev` package installed, you can compile an application with **librealsense** using `g++ -std=c++11 filename.cpp -lrealsense2` or an IDE of your choice.
 
+Reconnect the Intel RealSense depth camera and run: `realsense-viewer` to verify the installation.
+
+Verify that the kernel is updated :    
+`modinfo uvcvideo | grep "version:"` should include `realsense` string
 
-  Verify that the kernel is updated :    
-  `modinfo uvcvideo | grep "version:"` should include `realsense` string
+## Upgrading the Packages:
+When upgrading, be sure to:  
+- Remove the old records and update your source list:  
+  `sudo rm -f /etc/apt/sources.list.d/realsense-public.list`  
+  `sudo apt-get update`
 
 ## Uninstalling the Packages:
 **Important** Removing Debian package is allowed only when no other installed packages directly refer to it. For example removing `librealsense2-udev-rules` requires `librealsense2` to be removed first.