Add install doc (Fix #238) (#239)

README.md

@@ -234,6 +234,22 @@ cmake --build build --config Debug --target test
 
   _Note_: Use `--target RUN_TESTS` on the last line for `Visual Studio` and `--target RUN_TEST` for `XCode`.
 
+
+- install `cpu_features`
+  ```sh
+  cmake --build build --config Release --target install -v
+  ```
+
+  _Note_: Use `--target INSTALL` for `Visual Studio`.
+
+  _Note_: When using `Makefile` or `XCode` generator, you can use
+  [`DESTDIR`](https://www.gnu.org/software/make/manual/html_node/DESTDIR.html)
+  to install on a local repository.<br>
+  e.g.
+  ```sh
+  cmake --build build --config Release --target install -v -- DESTDIR=install
+  ```
+
 <a name="bindings"></a>
 ## Community bindings
 

cmake/README.md

@@ -17,7 +17,7 @@ or add cpu_features as a git-submodule in your project
 2- You can then use the cmake command `add_subdirectory()` to include
 cpu_features directly and use the `cpu_features` target in your project.
 
-3- Add the `cpu_features` target to the `target_link_libraries()` section of
+3- Add the `CpuFeature::cpu_features` target to the `target_link_libraries()` section of
 your executable or of your library.
 
 ## Disabling tests

cmake/ci/vagrant/freebsd/Vagrantfile

@@ -99,4 +99,9 @@ Vagrant.configure("2") do |config|
   cd project
   cmake --build build --target test -v
   SHELL
+  config.vm.provision "test", type: "shell", inline:<<-SHELL
+  set -x
+  cd project
+  cmake --build build --target install -v
+  SHELL
 end