message: Fix 'suport' typo in documentation
diff: @@ -178,7 +178,7 @@ in (harmless-but-inelegant) directory aliasing. For example, `crate` and
  `CrateTwo` have `{prefix}` values of `cr/at` and `Cr/at`; these are distinct on
  Unix machines but alias to the same directory on Windows. Using directories
  with normalized case avoids aliasing, but on case-sensitive filesystems it's
  -harder to suport older versions of Cargo that lack `{prefix}`/`{lowerprefix}`.
  +harder to support older versions of Cargo that lack `{prefix}`/`{lowerprefix}`.
  For example, nginx rewrite rules can easily construct `{prefix}` but can't
  perform case-conversion to construct `{lowerprefix}`.
  