Add libopenblas-dev in Requirements

Author: termoshtt

README.md

@@ -44,15 +44,20 @@ Supported features are following:
 | Feature          | Link type      | Requirements        | Description                                                                                    |
 |:-----------------|:---------------|:--------------------|:-----------------------------------------------------------------------------------------------|
 | openblas-static  | static         | gcc, gfortran, make | Build OpenBLAS in your project, and link it statically                                         |
-| openblas-system  | dynamic/static | -                   | Seek OpenBLAS in system, and link it                                                           |
+| openblas-system  | dynamic/static | libopenblas-dev     | Seek OpenBLAS in system, and link it                                                           |
 | netlib-static    | static         | gfortran, make      | Same as openblas-static except for using reference LAPACK                                      |
-| netlib-system    | dynamic/static | -                   | Same as openblas-system except for using reference LAPACK                                      |
+| netlib-system    | dynamic/static | liblapack-dev       | Same as openblas-system except for using reference LAPACK                                      |
 | intel-mkl-static | static         | (pkg-config)        | Seek static library of Intel MKL from system, or download if not found, and link it statically |
 | intel-mkl-system | dynamic        | (pkg-config)        | Seek shared library of Intel MKL from system, and link it dynamically                          |
 
 - You must use **just one** feature of them.
 - `dynamic/static` means it depends on what is found in the system. When the system has `/usr/lib/libopenblas.so`, it will be linked dynamically, and `/usr/lib/libopenblas.a` will be linked statically. Dynamic linking is prior to static linking.
-- `pkg-config` is used for searching Intel MKL packages in system, and it is optional. See [intel-mkl-src/README.md](https://github.com/rust-math/intel-mkl-src/blob/master/README.md#how-to-find-system-mkl-libraries) for detail.
+- Requirements notices:
+  - `gcc` and `gfortran` can be another compiler, e.g. `icc` and `ifort`.
+  - `libopenblas-dev` is package name in Debian, Ubuntu, and other derived distributions.
+    There are several binary packages of OpenBLAS, i.e. `libopenblas-{openmp,pthread,serial}-dev`.
+    It can be other names in other distributions, e.g. Fedora, ArchLinux, and so on.
+  - `pkg-config` is used for searching Intel MKL packages in system, and it is optional. See [intel-mkl-src/README.md](https://github.com/rust-math/intel-mkl-src/blob/master/README.md#how-to-find-system-mkl-libraries) for detail.
 
 ### For library developer