config: set up cargo profiles boilerplate

Cargo.toml

@@ -40,3 +40,19 @@ unsafe_code = "deny" # Exceptions must be discussed and deemed indispensable and
 pedantic = "warn"
 cargo = "warn"
 multiple_crate_versions = { level = "allow", priority = 1 } # https://git.nsb-software.de/devel/manifest/-/blob/main/policy.md#explicit-opt-out-of-clippymultiple_crate_versions
+
+[profile.dev]
+debug = 1 # Less precise locations.
+split-debuginfo="unpacked"
+
+[profile.dev.package."*"]
+debug = false # No debug symbols for deps.
+opt-level = 2 # Makes their code smaller too.
+
+[profile.dev.build-override]
+opt-level = 3
+
+[profile.release]
+lto = true
+debug = 1   # Keep debug symbols for now; less precise locations.
+# strip = true # Automatically strip symbols.