fix bold

Author: TylerMSFT

docs/build/reference/fo-object-file-name.md

@@ -11,8 +11,8 @@ Specifies an object (*`.obj`*) file name or directory to be used instead of the
 
 ## Syntax
 
-> **`/Fo"pathname"`\
-> **`/Fo:`**[** **]"pathname"`**
+> **`/Fo"pathname"`**\
+> **`/Fo:[ ]"pathname"`**
 
 ## Remarks