Add GitHub Bug Report and Feature Request Templates

[ChristianSilvermoon]

Having a template can encourage users to provide helpful information and provide better organization to the structure of issue reports

It can also help encourage users to include one issue per report

I've done my best to create flexible issue templates to help make tracking issues a little easier after noticing a few issue reports such as:

#109 Which looks like it intends to be a bulk list of issues built later, but for now contains a single Feature Request for Custom Control Bindings

#250 where the user is confused about whether or not their Feature Request counts as an issue and has made a long title as a result

#252 which appears to be a comment about #242 rather than its own issue

#263 Which is a possible duplicate of #223

#271 in which several unrelated issues are grouped together in a bulk list.

#305 which appears to be a #242 Duplicate

#308 in which a request for an Android port is made on a very vague "performance issue" report