[DOC] Add github templates

.github/CONTRIBUTING.md

+## Contributing is welcome
+
+Pull requests are welcome without an opening an issue. If you unsure about the feature or implementation open an issue and
+discuss your suggested changes. Meshviewer is a frontend application and the code needs to be loaded and 
+perform on slow mobile devices with many nodes and clients.

.github/ISSUE_TEMPLATE.md

+<!--- Provide a general summary of the issue in the Title above -->
+<!--- This template should help to improve the report, unneeded parts can be remvoed -->
+
+## Expected Behavior
+<!--- If you're describing a bug, tell us what should happen -->
+<!--- If you're suggesting a change/improvement, tell us how it should work -->
+
+## Current Behavior
+<!--- If describing a bug, tell us what happens instead of the expected behavior -->
+<!--- If suggesting a change/improvement, explain the difference from current behavior -->
+
+## Possible Solution
+<!--- Not obligatory, but suggest a fix/reason for the bug, -->
+<!--- or ideas how to implement the addition or change -->
+
+## Steps to Reproduce (for bugs)
+<!--- Provide a link to a live example, or an unambiguous set of steps to -->
+<!--- reproduce this bug. Include code to reproduce, if relevant -->
+1.
+2.
+3.
+4.
+
+## Context
+<!--- How has this issue affected you? What are you trying to accomplish? -->
+<!--- Providing context helps us come up with a solution that is most useful in the real world -->
+
+## Your Environment
+<!--- Include as many relevant details about the environment you experienced the bug in -->
+* Version used:
+* Browser Name and version:
+* Operating System and version (desktop or mobile):
+* Link to your project:

.github/PULL_REQUEST_TEMPLATE.md

+<!--- Use a prefix like [TASK], [BUGFIX], [DOC] or [CGL] and provide a general summary of your changes in the Title above -->
+
+## Description
+<!--- Describe your changes -->
+
+## Motivation and Context
+<!--- Why is this change required? What problem does it solve? -->
+<!--- If it fixes an open issue, please link to the issue here. -->
+
+## How Has This Been Tested?
+<!--- Please try to test the code in multiple browsers and also on a mobile device -->
+
+## Screenshots/links (if appropriate):
+
+## Checklist:
+<!--- Go over all the following points, and put an `x` in all the boxes that apply. -->
+<!--- If you're unsure about any of these, don't hesitate to ask. We're here to help! -->
+- [ ] My code follows the code style of this project. (CI will test it anyway and also needs approval)
+- [ ] My change requires a change to the documentation.
+- [ ] I have updated the documentation accordingly.