feat: Add if2 exercise

info.toml

@@ -87,6 +87,15 @@ Remember in Rust that:
 - `if`/`else` conditionals are expressions
 - Each condition is followed by a `{}` block."""
 
+[[exercises]]
+name = "if2"
+path = "exercises/if/if2.rs"
+mode = "test"
+hint = """
+For that first compiler error, it's important in Rust that each conditional
+block return the same type! To get the tests passing, you will need a couple
+conditions checking different input values."""
+
 # FUNCTIONS
 
 [[exercises]]