Simplify issue template

Author: Cito

.github/ISSUE_TEMPLATE/open-a-graphql-core-issue.md

@@ -0,0 +1,26 @@
+---
+name: Open a GraphQL-core issue
+about: General template for all GraphQL-core issues
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+# Questions regarding how to use GraphQL
+
+If you have a question on how to use GraphQL, please [post it to Stack Overflow](https://stackoverflow.com/questions/ask?tags=graphql) with the tag [#graphql](https://stackoverflow.com/questions/tagged/graphql).
+
+# Reporting issues with GraphQL-core 3
+
+Before filing a new issue, make sure an issue for your problem doesn't already exist and that this is not an issue that should be filed against a different repository (see below).
+
+The best way to get a bug fixed is to provide a _pull request_ with a simplified failing test case (or better yet, include a fix).
+
+# Reporting issues with GraphQL-core 2
+
+Please use the issue tracker of the [legacy repository](https://github.com/graphql-python/graphql-core-legacy) for issues with legacy versions of GraphQL-core.
+
+# Feature requests
+
+GraphQL-core is a Python port of the [GraphQL.js](https://github.com/graphql/graphql-js) reference implementation of the [GraphQL specification](https://github.com/graphql/graphql-spec). To discuss new features which are not Python specific, please open an issue against the GraphQL.js project. To discuss features that fundamentally change the way GraphQL works, open an issue against the specification.