typo fix

Author: Keenuts

clang/include/clang/Basic/AttrDocs.td

@@ -8535,9 +8535,9 @@ def HLSLSV_PositionDocs : Documentation {
 The ``SV_Position`` semantic, when applied to an input parameter in a pixel
 shader, contains the location of the pixel center (x, y) in screen space.
 This semantic can be applied to the parameter, or a field in a struct used
-as input parameter.
-This attribute is supported as input in pixel, hull, domain and mesh shaders.
-This attribute is supported as output in vertex, geometry and domain shaders.
+as an input parameter.
+This attribute is supported as an input in pixel, hull, domain and mesh shaders.
+This attribute is supported as an output in vertex, geometry and domain shaders.
 
 The full documentation is available here: https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-semantics
   }];