feat: import code from book with some improvement

.env.example

@@ -0,0 +1,6 @@
+POSTGRES_USER=postgres
+POSTGRES_PASSWORD=
+POSTGRES_HOST=localhost
+POSTGRES_PORT=5432
+POSTGRES_DB=rush
+PASETO_KEY=

.gitignore

@@ -1 +1,23 @@
-/target
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+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
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb
+
+# IDEA config files
+.idea
+
+# Vscode config files
+.vscode
+
+#Environment variables
+.env