Update issue templates (#1128)

https://blog.github.com/2018-05-02-issue-template-improvements/

.github/ISSUE_TEMPLATE/behavior-bug---plugin-incompatibility.md

@@ -0,0 +1,22 @@
+---
+name: Behavior Bug / Plugin Incompatibility
+about: Server Bug or Plugin Incompatibility
+
+---
+
+### What behaviour is expected:
+___What you expected to see___
+
+### What behaviour is observed:
+___What you actually saw___
+### Steps/models to reproduce:
+___This may include a build schematic, a video, or detailed instructions to help reconstruct the issue___
+
+### Plugin list:
+___A list of your plugins___
+
+### Paper build number:
+___This can be found by running `/version` on your server. `latest` is not a proper version number; we require the output of `/version` so we can properly track down the issue.___
+
+### Anything else:
+___Anything else you think may help us resolve the problem___

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,17 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.github/ISSUE_TEMPLATE/performance-problem.md

@@ -0,0 +1,23 @@
+---
+name: Performance problem
+about: Report performance problems or areas of concern
+
+---
+
+###  Timings or Profile link:
+___We ask that all timings/profiles are a link, not a screenshot. Screenshots inhibit our ability to figure out the real cause of the issue.___
+
+### Description of issue:
+___If applicable___
+
+### Plugin list:
+___All plugins running on the server___
+
+### bukkit.yml, spigot.yml, paper.yml, server.properties
+___Gist/pastebin/hastebin links___
+### Other helpful links
+___The more information we receive, the quicker and more effective we can be at finding the solution to the
+issue.___
+
+### Paper build number:
+___This can be found by running `/version` on your server. `latest` is not a proper version number; we require the output of `/version` so we can properly track down the issue.___

.github/ISSUE_TEMPLATE/server-crash---stacktrace.md

@@ -0,0 +1,19 @@
+---
+name: Server crash / Stacktrace
+about: Report server crashes and/or scary stacktraces
+
+---
+
+### Link/paste of stack trace
+
+    You can also simply just use code formatting in markdown!
+___We need all of the stack trace! Do not cut off parts of it.___
+
+### Plugin list:
+___A list of your plugins___
+
+### Actions to reproduce (if known):
+___This may include a build schematic, a video, or detailed instructions to help reconstruct the issue___
+
+### Paper build number:
+___This can be found by running `/version` on your server. `latest` is not a proper version number; we require the output of `/version` so we can properly track down the issue.___