MNT Uses GitHub's issue forms (scikit-learn#20744)

Co-authored-by: Olivier Grisel <[email protected]>

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,77 @@
+name: Bug Report
+description: Create a report to help us reproduce and correct the bug
+labels: ['Bug: triage']
+
+body:
+- type: markdown
+  attributes:
+    value: >
+      #### Before submitting a bug, please make sure the issue hasn't been already
+      addressed by searching through [the past issues](https://github.com/scikit-learn/scikit-learn/issues).
+- type: textarea
+  attributes:
+    label: Describe the bug
+    description: >
+      A clear and concise description of what the bug is.
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: Steps/Code to Reproduce
+    description: |
+      Please add a minimal example that we can reproduce the error by running the code. Be as succinct as possible, do not depend on external data. In short, we are going to copy-paste your code and we expect to get the same result as you. Example:
+
+      ```python
+      from sklearn.feature_extraction.text import CountVectorizer
+      from sklearn.decomposition import LatentDirichletAllocation
+      docs = ["Help I have a bug" for i in range(1000)]
+      vectorizer = CountVectorizer(input=docs, analyzer='word')
+      lda_features = vectorizer.fit_transform(docs)
+      lda_model = LatentDirichletAllocation(
+          n_topics=10,
+          learning_method='online',
+          evaluate_every=10,
+          n_jobs=4,
+      )
+      model = lda_model.fit(lda_features)
+      ```
+
+      If the code is too long, feel free to put it in a public gist and link it in the issue: https://gist.github.com.
+    placeholder: |
+      ```
+      Sample code to reproduce the problem
+      ```
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: Expected Results
+    description: >
+      Please paste or describe the expected results.
+    placeholder: >
+      Example: No error is thrown.
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: Actual Results
+    description: >
+      Please paste or describe the results you observe instead of the expected results. If you observe an error, please paste the error message including the **full** traceback of the exception.
+    placeholder: >
+      Please paste or specifically describe the actual output or traceback.
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: Versions
+    description: |
+      Please run the following and paste the output below.
+      ```python
+      import sklearn; sklearn.show_versions()
+      ```
+  validations:
+    required: true
+- type: markdown
+  attributes:
+    value: >
+      Thanks for contributing 🎉!

.github/ISSUE_TEMPLATE/config.yml

@@ -6,7 +6,7 @@ contact_links:
   - name: Stack Overflow
     url: https://stackoverflow.com/questions/tagged/scikit-learn
     about: Please ask and answer usage questions on Stack Overflow
-  - name: Mailing list 
+  - name: Mailing list
     url: https://mail.python.org/mailman/listinfo/scikit-learn
     about: General discussions and announcements on the mailing list
   - name: Gitter

.github/ISSUE_TEMPLATE/doc_improvement.yml

@@ -0,0 +1,17 @@
+name: Documentation improvement
+description: Create a report to help us improve the documentation. Alternatively you can just open a pull request with the suggested change.
+labels: [Documentation]
+
+body:
+- type: textarea
+  attributes:
+    label: Describe the issue linked to the documentation
+    description: >
+      Tell us about the confusion introduced in the documentation.
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: Suggest a potential alternative/fix
+    description: >
+      Tell us how we could improve the documentation in this regard.

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,25 @@
+name: Feature request
+description: Suggest a new algorithm, enhancement to an existing algorithm, etc.
+labels: ['New Feature']
+
+body:
+- type: markdown
+  attributes:
+    value: >
+      #### If you want to propose a new algorithm, please refer first to the [scikit-learn inclusion criterion](https://scikit-learn.org/stable/faq.html#what-are-the-inclusion-criteria-for-new-algorithms).
+- type: textarea
+  attributes:
+    label: Describe the workflow you want to enable
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: Describe your proposed solution
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: Describe alternatives you've considered, if relevant
+- type: textarea
+  attributes:
+    label: Additional context