chore: add issue templates (#2086)

* Add issue templates [skip ci]

* Apply suggestions from code review

Co-authored-by: Sascha Ißbrücker <sissbruecker@vaadin.com>

* Improve wording

Co-authored-by: Sascha Ißbrücker <sissbruecker@vaadin.com>

Author: yuriy-fix

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,81 @@
+---
+name: "\U0001F41B Bug Report"
+about: "Please report issues related to the TypeScript and HTML API of Vaadin components here."
+title: ''
+labels: 'i: needs triage'
+assignees: ''
+
+---
+
+<!--
+  Please fill out each section below, otherwise, your issue risks taking an infinite amount of time to triage. This info allows the maintainers team to diagnose and fix your issue as quickly as possible.
+
+  Before opening a new issue, please search existing issues: https://github.com/vaadin/web-components/issues.
+-->
+
+### Description
+
+Describe the issue that you're seeing.
+
+<!-- Example: The `vaadin-grid` element scrolls when applying filter. -->
+
+### Expected outcome
+
+What did you expect to happen?
+
+<!-- Example: No scrolling should happen. -->
+
+### Actual outcome
+
+What happened instead.
+
+<!-- Example: Grid content occasionally gets scrolled. -->
+
+### Live Demo (optional)
+
+A screenshot or video with issue reproduced.
+
+### Minimal reproducible example
+
+**Please** provide a demo project or code snippet that reproduces the issue, this _greatly_ increases the chance that we will be able to identify and fix the issue.
+
+<!--
+```
+<vaadin-grid></vaadin-grid>
+```
+```
+const grid = document.querySelector('vaadin-grid');
+grid.items = items;
+```
+-->
+
+### Steps to reproduce
+
+Clear steps describing how to reproduce the issue.
+
+<!-- Example
+1. Put a `vaadin-grid` element in the page.
+2. Add `vaadin-grid-filter` element to the column header template.
+3. Open the page in a web browser.
+4. Start typing in the filter input.
+-->
+
+### Environment
+
+- Version of the webcomponent / Vaadin platform.
+- OS.
+
+<!-- Example:
+- v20.0.0
+- OSX 10.13.4
+-->
+
+### Browsers Affected
+<!-- Check all that apply -->
+- [ ] Chrome
+- [ ] Firefox
+- [ ] Safari
+- [ ] Edge
+- [ ] IE 11
+- [ ] iOS Safari
+- [ ] Android Chrome

.github/ISSUE_TEMPLATE/config.yml

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+blank_issues_enabled: false

.github/ISSUE_TEMPLATE/feature_request.md

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+---
+name: "\U0001F680 Feature Request"
+about: "I have a specific suggestion for the TypeScript and HTML API of Vaadin components!"
+title: ''
+labels: 'i: needs triage'
+assignees: ''
+
+---
+
+### Describe your motivation
+
+A concise description of why you are proposing a change. For example, you would like a new feature to solve a use-case, or you want an existing feature changed because it is difficult to use.
+
+### Describe the solution you'd like
+
+Provide a clear and concise description of what you want to happen.
+
+### Describe alternatives you've considered
+
+Provide information about other solutions you've tried or researched.
+
+### Additional context
+
+Is there anything else you can add about the proposal?

.github/ISSUE_TEMPLATE/support_question.md

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+---
+name: "\U0001F917 Support Question"
+about: "If you have a question \U0001F4AC, please check out our Discord or StackOverflow!"
+title: ''
+labels: 'i: question, i: needs triage'
+assignees: ''
+
+---
+
+We primarily use GitHub as an issue tracker; for usage and support questions, please check out these resources below. Thank you!
+
+---
+
+* StackOverflow: https://stackoverflow.com/questions/tagged/vaadin using the tag `vaadin`
+* Discord: If it's just a quick question you can ask it on our Discord channel: https://discord.com/invite/MYFq5RTbBn
+* Also have a look at our website for more information on how to get support:
+  https://vaadin.com/support