Added pull request guidelines

.github/pull_request_template.md

@@ -0,0 +1,13 @@
+<!--
+
+Thank you for taking the time to contribute to Signale!
+
+For more info on how to contribute to the project, please read the [contributing guidelines](https://github.com/klauscfhq/signale/blob/master/contributing.md).
+
+We are always excited about pull requests!
+If the pull request fixes any open issues, reference the corresponding issues in the following fashion: `Fixes #321`.
+Including test results/screenshots/.gifs (if applicable/possible) alongside new features and bug fixes is something that we strongly encourage.
+
+Thank you so much again for all of your time invested in the project!
+
+-->