moved all crates into seperate folder + related path fixes

crates/compiler/can/src/lib.rs

@@ -0,0 +1,21 @@
+#![warn(clippy::dbg_macro)]
+// See github.com/rtfeldman/roc/issues/800 for discussion of the large_enum_variant check.
+#![allow(clippy::large_enum_variant)]
+pub mod abilities;
+pub mod annotation;
+pub mod builtins;
+pub mod constraint;
+pub mod def;
+pub mod effect_module;
+pub mod env;
+pub mod exhaustive;
+pub mod expected;
+pub mod expr;
+pub mod module;
+pub mod num;
+pub mod operator;
+pub mod pattern;
+pub mod procedure;
+pub mod scope;
+pub mod string;
+pub mod traverse;