Add pull request and issue templates (cvat-ai#1359)

* Add initial version of pull request template

* Fix links

* Fix codacy issues

* Slightly improve titles of sections

* Add a note about strikethough for the checklist.

* Fix progress of a pull request (each checkbox is an issue)

* Add the license header, checkboxes about the license.

* Updated the license

* Update the license to met https://github.com/licensee/licensee/blob/master/vendor/choosealicense.com/_licenses/mit.txt restrictions.

* Fix the pull request template name

* Make explaination text as comments (it will be visible when you edit the PR message)

* Add initial version of the issue template.

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,53 @@
+<!---
+Copyright (C) 2020 Intel Corporation
+
+SPDX-License-Identifier: MIT
+-->
+
+### My actions before raising this issue
+- [ ] Read/searched [the docs](https://github.com/opencv/cvat/tree/master#documentation)
+- [ ] Searched [past issues](/issues)
+
+<!--- Provide a general summary of the issue in the Title above -->
+
+### Expected Behaviour
+<!--- 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 Behaviour
+<!--- 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.
+1.
+1.
+1.
+
+### 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 -->
+- Git hash commit (`git log -1`):
+- Docker version `docker version` (e.g. Docker 17.0.05):
+- Are you using Docker Swarm or Kubernetes?
+- Operating System and version (e.g. Linux, Windows, MacOS):
+- Code example or link to GitHub repo or gist to reproduce problem:
+- Other diagnostic information / logs:
+    <details>
+    <summary>Logs from `cvat` container</summary>
+    </details>
+
+### Next steps
+You may [join our Gitter](https://gitter.im/opencv-cvat/public) channel for community support.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,46 @@
+<!---
+Copyright (C) 2020 Intel Corporation
+
+SPDX-License-Identifier: MIT
+-->
+
+<!-- Provide a general summary of your changes in the Title above -->
+
+### 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. Describe your changes in detail, add
+screenshots. -->
+
+### How has this been tested?
+<!-- Please describe in detail how you tested your changes.
+Include details of your testing environment, and the tests you ran to
+see how your change affects other areas of the code, etc. -->
+
+### Checklist
+<!-- Go over all the following points, and put an `x` in all the boxes that apply.
+If an item isn't applicable by a reason then ~~explicitly strikethrough~~ the whole
+line. If you don't do that github will show incorrect process for the pull request.
+If you're unsure about any of these, don't hesitate to ask. We're here to help! -->
+
+- [ ] I have raised an issue to propose this change ([required](https://github.com/opencv/cvat/issues))
+- [ ] My issue has received approval from the maintainers
+- [ ] I've read the [CONTRIBUTION](https://github.com/opencv/cvat/blob/develop/CONTRIBUTING.md) guide
+- [ ] I have added description of my changes into [CHANGELOG](https://github.com/opencv/cvat/blob/develop/CHANGELOG.md) file
+- [ ] I have updated the [documentation](
+  https://github.com/opencv/cvat/blob/develop/README.md#documentation) accordingly
+- [ ] I have added tests to cover my changes
+- [ ] I have linked related issues ([read github docs](
+  https://help.github.com/en/github/managing-your-work-on-github/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword))
+
+### License
+
+- [ ] I submit _my code changes_ under the same [MIT License](
+  https://github.com/opencv/cvat/blob/develop/LICENSE) that covers the project.
+  Feel free to contact the maintainers if that's a concern.
+- [ ] I have updated the license header for each file (see an example below)
+
+```python
+# Copyright (C) 2020 Intel Corporation
+#
+# SPDX-License-Identifier: MIT
+```

LICENSE

@@ -1,4 +1,6 @@
-Copyright (C) 2018 Intel Corporation
+MIT License
+
+Copyright (C) 2018-2020 Intel Corporation
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"),
@@ -18,4 +20,3 @@ OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
 OR OTHER DEALINGS IN THE SOFTWARE.
 
-SPDX-License-Identifier: MIT