Create PR template (#76)

fixed Issue #72

.github/pull_request_template.md

@@ -0,0 +1,14 @@
+[Insert URL to the product here.]
+
+## checklist
+
+Please make sure you've complied with the [contribution guidelines](https://github.com/agamm/awesome-developer-first/blob/main/CONTRIBUTING.md):
+- [ ] The homepage clearly states that the product is for developers.
+  > "Headless", "API-First", "SaaS" are frequently used keywords.
+  > Usually this means that the front page has some code examples :)
+- [ ] The product is available now and requires payment.
+- [ ] The PR has a descriptive title -- e.g., `Add {Product}`, not `Update README.md`.
+- [ ] The new submission isn't a duplicate.
+- [ ] The entry has a description, is sorted alphabetically, and ends with a full stop.
+
+Thanks!