(doc) documented WOMaxUploadSize

Documentation/SOGoInstallationGuide.asciidoc

@@ -370,6 +370,13 @@ Defaults to 10 (minutes).
 Do not set this too low as child processes replying to clients on a slow
 internet connection could be killed prematurely.
 
+|S |WOMaxUploadSize
+|Parameter used to set the maximum allowed size for content being
+sent to SOGo using a PUT or a POST call. This can also limit the file
+attachment size being uploaded to SOGo when composing a mail. The
+value is in kilobyte. By default, the value is 0, or disabled so no
+limit will be set.
+
 |S |SxVMemLimit
 |Parameter used to set the maximum amount of memory (in
 megabytes) that a child can use. Reaching that value will force children