setup CI and tidy to use typos for spellchecking and fix few typos

compiler/rustc_attr_parsing/src/attributes/cfg.rs

@@ -14,7 +14,7 @@ use crate::{fluent_generated, parse_version};
 
 /// Emitter of a builtin lint from `cfg_matches`.
 ///
-/// Used to support emiting a lint (currently on check-cfg), either:
+/// Used to support emitting a lint (currently on check-cfg), either:
 ///  - as an early buffered lint (in `rustc`)
 ///  - or has a "normal" lint from HIR (in `rustdoc`)
 pub trait CfgMatchesLintEmitter {

compiler/rustc_attr_parsing/src/context.rs

@@ -187,7 +187,7 @@ impl Stage for Late {
     }
 }
 
-/// used when parsing attributes for miscelaneous things *before* ast lowering
+/// used when parsing attributes for miscellaneous things *before* ast lowering
 pub struct Early;
 /// used when parsing attributes during ast lowering
 pub struct Late;