[core] Polish issue templates

.github/ISSUE_TEMPLATE/1.bug.yml

@@ -4,15 +4,13 @@ labels: ['status: waiting for maintainer']
 body:
   - type: markdown
     attributes:
-      value: |
-        Please provide a searchable summary of the issue in the title above ⬆️.
-
-        Thanks for contributing by creating an issue! ❤️
+      value: Thanks for contributing by creating an issue! ❤️ Please provide a searchable summary of the issue in the title above ⬆️.
   - type: input
     attributes:
       label: Search keywords
-      description: Your issue may have already been reported! List the keywords you've used to search the [existing issues](https://github.com/mui/mui-public/issues). This will also make your issue searchable for others.
-      placeholder: e.g. datagrid column resizing
+      description: |
+        Your issue may have already been reported! First search for duplicates among the [existing issues](https://github.com/mui/mui-public/issues).
+        If your issue isn't a duplicate, great! Please list the keywords you used so people in the future can find this one more easily:
     validations:
       required: true
   - type: checkboxes
@@ -45,7 +43,7 @@ body:
   - type: textarea
     attributes:
       label: Context
-      description: What are you trying to accomplish? How has this issue affected you? Providing context helps us come up with a solution that is more useful in the real world.
+      description: What are you trying to accomplish? Providing context helps us come up with a solution that is more useful in the real world.
   - type: textarea
     attributes:
       label: Your environment

.github/ISSUE_TEMPLATE/2.feature.yml

@@ -4,17 +4,15 @@ labels: ['status: waiting for maintainer']
 body:
   - type: markdown
     attributes:
-      value: |
-        Please provide a searchable summary of the issue in the title above ⬆️.
-
-        Thanks for contributing by creating an issue! ❤️
-  - type: checkboxes
+      value: Thanks for contributing by creating an issue! ❤️ Please provide a searchable summary of the issue in the title above ⬆️.
+  - type: input
     attributes:
-      label: Duplicates
-      description: Please [search the history](https://github.com/mui/material-ui/issues) to see if an issue already exists for the same problem.
-      options:
-        - label: I have searched the existing issues
-          required: true
+      label: Search keywords
+      description: |
+        Your issue may have already been reported! First search for duplicates among the [existing issues](https://github.com/mui/mui-public/issues).
+        If your issue isn't a duplicate, great! Please list the keywords you used so people in the future can find this one more easily:
+    validations:
+      required: true
   - type: checkboxes
     attributes:
       label: Latest version
@@ -33,4 +31,4 @@ body:
   - type: textarea
     attributes:
       label: Motivation
-      description: What are you trying to accomplish? How has the lack of this feature affected you? Providing context helps us come up with a solution that is more useful in the real world.
+      description: What are you trying to accomplish? Providing context helps us come up with a solution that is more useful in the real world.

.github/ISSUE_TEMPLATE/3.rfc.yml

@@ -12,7 +12,7 @@ body:
   - type: textarea
     attributes:
       label: What's the problem?
-      description: Write a short paragraph or bulleted list to briefly explain what you're trying to do, what outcomes you're aiming for, and any other relevant details to help us understand the motivation behind this RFC.
+      description: Write a short paragraph or bulleted list to briefly explain what you're trying to do, what outcomes you're aiming for.
   - type: textarea
     attributes:
       label: What are the requirements?
@@ -35,4 +35,4 @@ body:
   - type: textarea
     attributes:
       label: Resources and benchmarks
-      description: Attach any issues, PRs, links, documents, etc… that might be relevant to the RFC
+      description: Attach any issues, PRs, links, documents, etc… that might be relevant to the RFC.