Update .gitignore (#229)

Author: tim-blackbird

.gitignore

@@ -1,22 +1,20 @@
 # Generated by Cargo
 # will have compiled files and executables
-debug/
-target/
+target
 
 # Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
 # More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
 Cargo.lock
 
+# Local cargo config overrides
+.cargo/config
+.cargo/config.toml
+
 # These are backup files generated by rustfmt
 **/*.rs.bk
 
 # MSVC Windows builds of rustc generate these, which store debugging information
 *.pdb
 
-
-# Added by cargo
-
-/target
-
 # mdbook generated files
 design-book/book