remove trailing spaces

Author: atifali

documentation/README.md

@@ -233,14 +233,14 @@ required path and other environment variables.
 
 Some host builds of EPICS require that the environment variable
 `EPICS_HOST_ARCH` be defined. The shell script `EpicsHostArch` in the
-`base/startup` directory (which finds and calls the perl script 
-`EpicsHostArch.pl` in the `base/src/tools` directory) prints the 
-value which the build will use if the variable is not set before 
-the build starts. Architecture names start with the operating system 
-followed by a dash and the host CPU architecture, e.g. `linux-x86_64`. 
-Some architecture names have another dash followed by another keyword, 
-for example when building for Windows but using the MinGW compiler the 
-name must be `windows-x64-mingw`. See `configure/CONFIG_SITE` for a 
+`base/startup` directory (which finds and calls the perl script
+`EpicsHostArch.pl` in the `base/src/tools` directory) prints the
+value which the build will use if the variable is not set before
+the build starts. Architecture names start with the operating system
+followed by a dash and the host CPU architecture, e.g. `linux-x86_64`.
+Some architecture names have another dash followed by another keyword,
+for example when building for Windows but using the MinGW compiler the
+name must be `windows-x64-mingw`. See `configure/CONFIG_SITE` for a
 list of supported host architecture names.
 
 * **`PATH`**