Cleanup the setup instructions and rename the windows setup scripts

setup/windows_install.bat

@@ -0,0 +1,47 @@
+@echo off
+
+:: Check for Python Installation
+echo.
+echo Looking for Python
+python --version 2>NUL
+if errorlevel 1 goto errorNoPython
+echo Python found. OK.
+
+if exist setup.py (
+    echo setup.py found. OK.
+) else (
+    cd ..
+    if exist setup.py (
+        echo setup.py found. OK.
+    ) else (
+        goto errorNoSetup
+    )
+)
+echo.
+
+:: Install the PyQt5, lxml and pyenchant dependencies
+pip install --user pywin32 -r requirements.txt
+
+:: Create the desktop and start menu icons
+python setup.py win-install
+
+pause
+goto:eof
+
+:errorNoPython
+echo.
+echo ERROR^: Python is not installed on your system, or cannot be found.
+echo.
+echo Please download and install it from https://www.python.org/downloads/
+echo Also make sure the "Add Python to PATH" option is selected during installation.
+echo.
+goto:eof
+
+:errorNoSetup
+echo.
+echo ERROR^: Could not find the setup.py script.
+echo.
+echo Make sure you run setup.py from the novelWriter root folder.
+echo.
+
+pause