Update installing.rst

Replaces and based on esp8266#5602
Fixes esp8266#5583

Author: devyte

doc/installing.rst

@@ -101,6 +101,15 @@ Instructions - Windows 10
                    --- boards.txt
                    --- LICENSE
 
+-  Initialize the submodules
+
+   .. code:: bash
+
+       cd %USERPROFILE%\Documents\hardware\esp8266com\esp8266
+       git submodules update --init   
+  
+  If error messages about missing files related to ``SoftwareSerial`` are encountered during the build process, it should be because this step was missed and is required.
+  
 -  Download binary tools
 
    .. code:: bash
@@ -112,16 +121,6 @@ Instructions - Windows 10
 
 - If using the Arduino IDE for Visual Studio (https://www.visualmicro.com/), be sure to click Tools - Visual Micro - Rescan Toolchains and Libraries 
 
--  You may see some error messages about missing files related to the
-   ``SoftwareSerial`` library. These are because the ESP8266 version
-   of this library has been moved to a separate git submodule. In
-   order to get rid of these messages, initialize the submodule:
-
-   .. code:: bash
-
-       cd %USERPROFILE%\Documents\hardware\esp8266com\esp8266
-       git submodules update --init   
-  
 -  When later updating your local library, goto the esp8266 directory and do a git pull
 
    .. code:: bash
@@ -176,6 +175,15 @@ Instructions - Other OS
                    --- boards.txt
                    --- LICENSE
 
+-  Initialize the submodules
+
+   .. code:: bash
+
+       cd esp8266
+       git submodules update --init   
+  
+  If error messages about missing files related to ``SoftwareSerial`` are encountered during the build process, it should be because this step was missed and is required.
+
 -  Download binary tools
 
    .. code:: bash