Update issue & PR templates (#2618)

* New issue template

* Update PULL_REQUEST_TEMPLATE.md

* Update ISSUE_TEMPLATE.md

.github/ISSUE_TEMPLATE.md

@@ -1,59 +1,144 @@
-If you are reporting a bug, please fill in below. Otherwise feel free to remove this template entirely.
+<!--
+  PLEASE DON'T DELETE THIS TEMPLATE UNTIL YOU HAVE READ THE FIRST SECTION.
+-->
+
+### Is this a bug report?
+
+(write your answer here)
+
+<!--
+  If you answered "Yes":
+
+    We expect that it will take you about 30 minutes to produce a high-quality bug report.
+    While this may seem like a lot, putting care into issues helps us fix them faster.
+    For bug reports, it is REQUIRED to fill the rest of this template, or the issue will be closed.
+
+  If you answered "No":
+
+    If this is a question or a discussion, you may delete this template and write in a free form.
+    Note that we don't provide help for webpack questions after ejecting.
+    You can find webpack docs at https://webpack.js.org/.
+
+  Now let's get started!
+-->
 
 ### Can you reproduce the problem with npm 4.x?
 
-Many errors, especially related to "missing modules", are due to npm bugs.
+<!--
+  Many errors, especially related to "missing modules", are due to npm bugs.
+  Which version of npm are you running? You can find out by checking:
 
-Try to update npm to 4.x first:
+    npm -v
 
-```
-npm install -g npm@4
+  If it's not starting with 4, try to install npm 4.x:
 
-cd your_project_directory
-rm -rf node_modules
-npm install
-```
+    npm install -g npm@4
+    cd your_project_directory
+    rm -rf node_modules
+    npm cache clear
+    npm install
 
-**This is especially important if `npm -v` gives you 5 because npm 5 is [known to have many issues](https://github.com/npm/npm/issues/16991).**
+  Then try to reproduce the issue again.
+  Can you still reproduce it?
 
-Then try to reproduce the issue again.
+  Note: Please try this even if you are using Yarn. Yarn also has bugs.
+-->
 
-Can you still reproduce it?
+(Write your answer here.)
 
-### Description
+### Have you read the Troubleshooting section and searched the User Guide?
 
-What are you reporting?
+<!--
+  There are a few common documented problems, such as watcher not detecting changes.
+  They are described in the Troubleshooting section of the User Guide:
 
-### Expected behavior
+  https://github.com/facebookincubator/create-react-app/blob/master/packages/react-scripts/template/README.md#troubleshooting
 
-Tell us what you think should happen.
+  Have you read that section, and have you searched the User Guide for symptoms of your problem?
+  Please write the answer below:
+-->
 
-### Actual behavior
-
-Tell us what actually happens.
+(Write your answer here.)
 
 ### Environment
 
-Run these commands in the project folder and fill in their results:
+<!--
+  Please fill in all the relevant fields by running these commands in terminal.
+-->
 
-1. `npm ls react-scripts` (if you haven’t ejected): 
-2. `node -v`: 
-3. `npm -v`:
+1. `node -v`: 
+2. `npm -v`:
+4. `yarn --version` (if you use Yarn):
+3. `npm ls react-scripts` (if you haven’t ejected): 
 
 Then, specify:
 
 1. Operating system:
-2. Browser and version:
+2. Browser and version (if relevant):
+
+### Steps to Reproduce
+
+<!--
+  How would you describe your issue to someone who doesn’t know you or your project?
+  Try to write a sequence of steps that anybody can repeat to see the issue.
+-->
+
+(Write your steps here:)
+
+1. 
+2. 
+3. 
+
+### Expected Behavior
+
+<!--
+  How did you expect the tool to behave?
+  It’s fine if you’re not sure your understanding is correct.
+  Just write down what you thought would happen.
+-->
+
+(Write what you thought would happen.)
+
+### Actual Behavior
+
+<!--
+  Did something go wrong?
+  Is something broken, or not behaving as you expected?
+  Describe this section in detail, and attach screenshots if possible.
+-->
+
+(Write what happened. Add screenshots!)
 
 ### Reproducible Demo
 
-Please take the time to create a new app that reproduces the issue.
+<!--
+  Please share a project that reproduces the issue.
+  There are two ways to do it:
 
-Alternatively, you could copy your app that experiences the problem and start removing things until you’re left with the minimal reproducible demo.
+    * Create a new app and try to reproduce the issue in it.
+      This is useful if you roughly know where the problem is, or can’t share the real code.
 
-(Accidentally, you might get to the root of your problem during that process.)
+    * Or, copy your app and remove things until you’re left with the minimal reproducible demo.
+      This is useful for finding the root cause. You may then optionally create a new project.
 
-Push to GitHub and paste the link here.
+  This is a good guide to creating bug demos: https://stackoverflow.com/help/mcve
+  Once you’re done, push the project to GitHub and paste the link to it below:
+-->
 
-By doing this, you're helping the Create React App contributors a big time!
-Demonstrable issues gets fixed faster.
+(Paste the link to an example project and exact instructions to reproduce the issue.)
+
+<!--
+  What happens if you skip this step?
+
+  Someone will read your bug report, and maybe will be able to help you,
+  but it’s unlikely that it will get much attention from the team. Eventually,
+  the issue will likely get closed in favor of issues that have reproducible demos.
+
+  Please remember that:
+
+    * Issues without reproducible demos have a very low priority.
+    * The person fixing the bug would have to do that anyway. Please be respectful of their time.
+    * You might figure out the issues yourself as you work on extracting it.
+
+  Thanks for helping us help you!
+-->

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,8 +1,7 @@
 <!--
 Thank you for sending the PR!
-If you changed any code, there are just two more things to do:
 
-* Provide us with clear instructions on how you verified your changes work. Bonus points for screenshots!
+If you changed any code, please provide us with clear instructions on how you verified your changes work. Bonus points for screenshots!
 
 Happy contributing!
 -->