Link Travis CI badge to build status [skip ci]

Right now, clicking on the Travis CI badge just opens the image itself.

With this change, it links to the current build status dashboard, which
is much more useful.

README.md

@@ -6,7 +6,9 @@
 
 <p>
     <p align="center">
+      <a href="https://app.travis-ci.com/github/AykutSarac/jsoncrack.com">
         <img alt="travis ci badge" src="https://img.shields.io/travis/com/AykutSarac/jsoncrack.com/main?style=flat-square" />
+      </a>
       <a href="https://github.com/AykutSarac/jsoncrack.com/blob/main/LICENSE">
         <img alt="license badge" src="https://img.shields.io/github/license/AykutSarac/jsoncrack.com?style=flat-square" />
       </a>