fix: a bunch of typos

This PR will fix some typos detected by [typos].

There are also some other typos in the function names, variable names, and file
names, which I leave as they are. I'm more certain that typos in comments
should be fixed.

[typos]: https://github.com/crate-ci/typos

crates/hir-expand/src/lib.rs

@@ -616,7 +616,7 @@ impl ExpansionInfo {
 
         let token_id = match token_id_in_attr_input {
             Some(token_id) => token_id,
-            // the token is not inside an attribute's input so do the lookup in the macro_arg as ususal
+            // the token is not inside an attribute's input so do the lookup in the macro_arg as usual
             None => {
                 let relative_range =
                     token.value.text_range().checked_sub(self.arg.value.text_range().start())?;