build: use issue forms for issue creation

.github/ISSUE_TEMPLATE/bug.yml

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+name: Bug Report
+description: Report a bug in Angular Material or the CDK
+title: "bug(COMPONENT): TITLE"
+labels: ["needs triage"]
+body:
+  - type: checkboxes
+    id: is-regression
+    attributes:
+      label: Is this a regression?
+      description: Did this behavior use to work in the previous version?
+      options:
+        - label: Yes, this behavior used to work in the previous version
+  - type: input
+    id: version-bug-was-not-present
+    attributes:
+      label: The previous version in which this bug was not present was
+    validations:
+      required: false
+  - type: textarea
+    id: description
+    attributes:
+      label: Description
+      description: A clear and concise description of the problem.
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Reproduction
+      description: |
+        **Use StackBlitz to reproduce your issue:**
+        - [Components](https://stackblitz.com/fork/components-issue)
+        - [Harnesses](https://stackblitz.com/fork/harness-issue)
+      value: |
+        Steps to reproduce:
+        1. 
+        2. 
+    validations:
+      required: true
+  - type: textarea
+    id: expected-behavior
+    attributes:
+      label: Expected Behavior
+      description: What behavior were you expecting to see?
+    validations:
+      required: true
+  - type: textarea
+    id: actual-behavior
+    attributes:
+      label: Actual Behavior
+      description: What behavior did you actually see?
+    validations:
+      required: true
+  - type: textarea
+    id: environment
+    attributes:
+      label: Environment
+      description: You can use `ng version` command.
+      value: |
+        - Angular:
+        - CDK/Material:
+        - Browser(s):
+        - Operating System (e.g. Windows, macOS, Ubuntu):
+    validations:
+      required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Angular Framework
+    url: https://github.com/angular/angular/issues/new
+    about: Issues and feature requests for Angular Framework

.github/ISSUE_TEMPLATE/docs.yml

@@ -0,0 +1,21 @@
+name: Documentation
+description: Suggest an improvement to our documentation at material.angular.io
+title: "docs-bug(COMPONENT): TITLE"
+labels: ["docs", "needs triage"]
+body:
+  - type: textarea
+    id: description
+    attributes:
+      label: Documentation Feedback
+      description: |
+        Provide a brief summary of what you would like to see changed in our documentation at [material.angular.io](https://material.angular.io/).
+        Feel free to provide any suggestions of content or examples you’d like us to include.
+    validations:
+      required: true
+  - type: input
+    id: affected-documentation-page
+    attributes:
+      label: Affected documentation page
+      description: Insert a link to the affected page on [material.angular.io](https://material.angular.io/).
+    validations:
+      required: true

.github/ISSUE_TEMPLATE/feature.yml

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+name: Feature
+description: Propose a new feature for Angular Material or the CDK
+title: "feat(COMPONENT): TITLE"
+labels: ["feature", "needs triage"]
+body:
+  - type: textarea
+    id: description
+    attributes:
+      label: Feature Description
+      description: Provide a brief summary of the feature you would like to see.
+    validations:
+      required: true
+  - type: textarea
+    id: use-case
+    attributes:
+      label: Use Case
+      description: Describe the use case(s) that the proposed feature would enable.
+    validations:
+      required: false

.github/ISSUE_TEMPLATE/troubleshooting.yml

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+name: Troubleshooting
+description: Request for help on an issue you are facing with Angular Material or the CDK
+title: "help(COMPONENT): TITLE"
+labels: ["troubleshooting", "needs triage"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        The Angular team can't provide general troubleshooting help. However, the extended community of users can provide more help:
+        - [StackOverflow](https://stackoverflow.com/questions/tagged/angular-material2)
+        - [Gitter](https://gitter.im/angular/material2)
+        - [Google Groups](https://groups.google.com/forum/#!forum/angular-material2)
+
+        Issues should capture only bug reports and feature requests. However, we understand that it is not always clear whether an issue is caused by a bug or incorrect usage of a feature/component.
+        Most support requests will be automatically closed. If the answer is quickly obvious, though, we might be able to provide a brief answer.
+  - type: textarea
+    id: description
+    attributes:
+      label: What are you trying to do?
+    validations:
+      required: true
+  - type: textarea
+    id: troubleshooting-steps
+    attributes:
+      label: What troubleshooting steps have you tried?
+      description: What are you seeing that does not match your expectations?
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Reproduction
+      description: |
+        We can only help if we can reproduce the problem ourselves.
+        **Use StackBlitz to demonstrate what you are trying to do:**
+        - [Components](https://stackblitz.com/fork/components-issue)
+        - [Harnesses](https://stackblitz.com/fork/harness-issue)
+      value: |
+        Steps to reproduce:
+        1. 
+        2. 
+    validations:
+      required: true
+  - type: textarea
+    id: environment
+    attributes:
+      label: Environment
+      description: You can use `ng version` command.
+      value: |
+        - Angular:
+        - CDK/Material:
+        - Browser(s):
+        - Operating System (e.g. Windows, macOS, Ubuntu):
+    validations:
+      required: true