message: Fix the "--cflags" part of "wasmer config" in README.md
diff: @@ -184,9 +184,9 @@ $ wasmer config --libs
  -L/Users/myuser/.wasmer/lib -lwasmer
  ```
  -### `wasmer config --libs`
  +### `wasmer config --cflags`
  -Libraries needed to link against Wasmer components:
  +Headers needed to build against Wasmer components:
  ```bash
  $ wasmer config --cflags
  