grammer -> grammer

Author: gottesmm

proposals/0000-compiler-settings.md

@@ -145,7 +145,7 @@ the compiler options discoverable to the user in the IDE.
 
 ## Detailed design
 
-We will update the swift grammer to allow for a new top level statement called
+We will update the swift grammar to allow for a new top level statement called
 `compilerSettings` that takes a list of expressions:
 
 ```text