update issue template to include commonly needed info

Author: shellscape

.github/ISSUE_TEMPLATE.md

@@ -1,15 +1,50 @@
-<!-- Before creating an issue please make sure you are using the latest version of webpack-dev-server and webpack. -->
+> **Please note that this template is not optional.** If you proceed with this form,
+please fill out _all_ fields, or your issue may be closed as "invalid."
+Please do not delete this template. Please ask questions on StackOverflow or the
+webpack Gitter (https://gitter.im/webpack/webpack). _General questions, how-to
+questions, and support requests will be closed._
+**Please do remove this header to acknowledge this message.**
 
-**Do you want to request a *feature* or report a *bug*?**
-<!-- Please ask questions on StackOverflow or the webpack Gitter (https://gitter.im/webpack/webpack). Questions will be closed. -->
+* Operating System:
+* Node Version:
+* NPM Version:
+* webpack Version:
+* webpack-dev-server Version:
 
-**What is the current behavior?**
+<!-- Please place an x, no spaces, in all [ ] that apply -->
 
-**If the current behavior is a bug, please provide the steps to reproduce.**
-<!-- A great way to do this is to provide your configuration via a GitHub gist. -->
+- [ ] This is a **feature** request
+- [ ] This is a **bug**
 
-**What is the expected behavior?**
+### Code
 
-**If this is a feature request, what is motivation or use case for changing the behavior?**
+<!--
+  If you have a large amount of code to share which demonstrates the problem
+  you're experiencing, or your webpack config is very large, please provide a link
+  to your repository rather than pasting code. We'd also encourage you to use a
+  Github Gist link instead of pasting code. Otherwise, please paste relevant
+  short snippets below.
+
+  For bugs, please do consider providing a link to a stripped-down, bare-bones
+  repo that can reproduce the problem you're experiencing. Many times, bugs
+  aren't actual bugs, but rather specific issues with loaders, plugins, or
+  an environment/OS. Problems with complicated or large applications will almost
+  always require this to be triaged.
+-->
+
+```js
+  // webpack.config.js
+```
+
+```js
+  // additional code, remove if not needed.
+```
+
+### Expected Behavior
+
+### Actual Behavior
+
+### For Bugs; How can we reproduce the behavior?
+
+### For Features; What is the motivation and/or use-case for the feature?
 
-**Please mention your webpack and Operating System version.**