message: doc: add split-debuginfo doc in config chapter
diff: @@ -94,6 +94,7 @@ offline = false # do not access the network
  [profile.<name>] # Modify profile settings via config.
  opt-level = 0 # Optimization level.
  debug = true # Include debug info.
  +split-debuginfo = '...' # Debug info splitting behavior.
  debug-assertions = true # Enables debug assertions.
  overflow-checks = true # Enables runtime integer overflow checks.
  lto = false # Sets link-time optimization.
  @@ -603,6 +604,13 @@ See [codegen-units](profiles.md#codegen-units).
  See [debug](profiles.md#debug).
  +##### `profile.<name>.split-debuginfo`
  +* Type: string
  +* Default: See profile docs.
  +* Environment: `CARGO_PROFILE_<name>_SPLIT_DEBUGINFO`
  +
  +See [split-debuginfo](profiles.md#split-debuginfo).
  +
  ##### `profile.<name>.debug-assertions`
  * Type: boolean
  * Default: See profile docs.
  