Update "See also" section in *.md files

Create an horizontal rule right before the block.

CONTRIBUTING.md

@@ -139,3 +139,12 @@ No test should fail.
 
 You can tweak the PHPUnit's settings by copying `phpunit.xml.dist` to `phpunit.xml`
 and changing it according to your needs.
+
+***
+
+See also:
+
+- [Feature Guide](docs/README.md)
+- [Installation](docs/INSTALL.md)
+- [License](LICENSE.md)
+- [Validators](docs/VALIDATORS.md)

LICENSE.md

@@ -28,3 +28,12 @@ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+***
+
+See also:
+
+- [Contributing](CONTRIBUTING.md)
+- [Feature Guide](docs/README.md)
+- [Installation](docs/INSTALL.md)
+- [Validators](docs/VALIDATORS.md)

docs/INSTALL.md

@@ -7,6 +7,8 @@ you can install it using [Composer](http://getcomposer.org).
 composer require respect/validation
 ```
 
+***
+
 See also:
 
 - [Contributing](../CONTRIBUTING.md)

docs/README.md

@@ -210,6 +210,8 @@ Message:
 "really messed up screen#name" must contain only letters (a-z) and digits (0-9)
 ```
 
+***
+
 See also:
 
 - [Contributing](../CONTRIBUTING.md)

docs/VALIDATORS.md

@@ -260,6 +260,8 @@
   * [Yes](Yes.md)
   * [Zend](Zend.md)
 
+***
+
 See also:
 
 - [Contributing](../CONTRIBUTING.md)