Merge pull request #2287 from Jarod42/doc_unsignedchar

[doc] Write doc for `unsignedchar`

website/docs/unsignedchar.md

@@ -1,12 +1,20 @@
-unsignedchar - This page was auto-generated. Feel free to help us improve the documentation by creating a pull request.
+Force sign of `char`
 
 ```lua
 unsignedchar (value)
 ```
 
+Note that `char` is still a distinct type from `signed char` and `unsigned char`.
+
 ### Parameters ###
 
-`value` - needs documentation.
+`value` is one of:
+
+
+* Off: Make `char` signed. (default on msc)
+* On: Make `char` unsigned.
+
+Don't use that api to have default for gcc/clang
 
 ## Applies To ###
 
@@ -19,6 +27,5 @@ Premake 5.0.0 alpha 14 or later.
 ### Examples ###
 
 ```lua
-unsignedchar (value)
+unsignedchar "On"
 ```
-