Cleanup of rAthena templates and docs (#5566)

Moves the logo to doc/.
Adds a Feature Request template when creating issues.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,26 @@
+<!-- NOTE: Anything within these brackets will be hidden on the preview of the Feature Request. -->
+
+**Is your request related to a missing feature?**
+
+<!--
+  Provide a clear and concise description of what the feature pertains to.
+-->
+
+**Describe the solution you'd like**
+
+<!--
+  Provide a clear and concise description of what you want to happen.
+-->
+
+**Describe alternatives you've considered**
+
+<!--
+  Let us know about other solutions you've tried or researched.
+-->
+
+**Additional context**
+
+<!--
+  Is there anything else you can add about the proposal?
+  You might want to link to related issues here if you haven't already.
+-->

README.md

@@ -1,4 +1,4 @@
-<img src="branding/logo.png" align="right" height="90" />
+<img src="doc/logo.png" align="right" height="90" />
 
 # rAthena
 [![Build Status](https://travis-ci.org/rathena/rathena.png?branch=master)](https://travis-ci.org/rathena/rathena) [![Build status](https://ci.appveyor.com/api/projects/status/8574b8nlwd57loda/branch/master?svg=true)](https://ci.appveyor.com/project/rAthenaAPI/rathena/branch/master) [![Total alerts](https://img.shields.io/lgtm/alerts/g/rathena/rathena.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/rathena/rathena/alerts/) [![Language grade: C/C++](https://img.shields.io/lgtm/grade/cpp/g/rathena/rathena.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/rathena/rathena/context:cpp) ![GitHub](https://img.shields.io/github/license/rathena/rathena.svg) ![GitHub repo size](https://img.shields.io/github/repo-size/rathena/rathena.svg)