Add feature request/enhancement/question issue template

[welljsjs]

Most issues filed by external people or users of this project do not use the issue template, probably because the template is mainly intended to report bugs, not feature or enhancement requests.

This issue aims to solve the above problem by creating a mockup for the feature request template.

To Do:

• Header (title)
• ensure feature request is reported for the correct repository
• body (additional questions & description)
• footer (if necessary)

Template:

Please notice that issues where this template is not filled out correctly won't receive an answer and get discarded and closed.

Please delete the parts of the template that are not needed.

Please remove these lines of text (beginning and ending with three backticks) before submitting the issue.

Prerequisites

Please answer the following questions for yourself before submitting an issue.

• I checked to make sure that this feature request/question has not already been filed
• I'm reporting the issue to the correct repository as it is related to this repository and not to the official pjsip repository
• I checked the README and found no answer
• I am running the latest version

Feature/Question Summary

Please provide a brief description/summary of the feature/question.

Solves the following problems (only relevant for feature requests):

If you file a feature request, please state which existing problems/issues this feature request may solve.

Detailed description

Please provide a detailed description of the feature request/question here.

Environment (only if relevant for feature requests)

Please provide any relevant information about your setup. This is important in case the issue is not reproducible except for under certain conditions.

• Xcode Version:
• Platform and architecture building for:
• Operating System:
• SDK version:
  (if you're using any other SDK than the one shipped with the specified Xcode version)

[welljsjs]

Solved by #105