Insert a link to contributing guidelines in PR template

Author: faisalman

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,6 +1,6 @@
 # Prerequisites
 
-- [ ] I have read and follow the contributing guidelines
+- [ ] I have read and follow the [contributing](https://github.com/faisalman/ua-parser-js/blob/master/CONTRIBUTING.md) guidelines
 - [ ] I have read and accept the [Contributor License Agreement (CLA)](https://gist.github.com/faisalman/2ed16621ebb544157eba85a7f7381417) Document and I hereby sign the CLA
 
 # Type of Change

CONTRIBUTING.md

@@ -4,4 +4,4 @@
 * Make some changes as required
 * Write unit test to showcase its functionality under `/test`
 * Run the test suites to make sure it's not breaking anything `$ npm run build+test`
-* Submit a pull request under `develop` branch & check the CLA in the submission form
+* Submit a pull request & check the CLA in the submission form