Split the unified PR template into few (#82734)

Ref: https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/creating-a-pull-request-template-for-your-repository

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,25 +0,0 @@
-##### SUMMARY
-
-<!--- Describe the change below, including rationale and design decisions -->
-
-<!--- HINT: Include "Fixes #nnn" if you are fixing an existing issue -->
-
-##### ISSUE TYPE
-
-<!--- Pick one below and delete the rest -->
-
-- Bugfix Pull Request
-- Docs Pull Request
-- Feature Pull Request
-- Test Pull Request
-
-##### ADDITIONAL INFORMATION
-
-<!--- Include additional information to help people understand the change here -->
-<!--- A step-by-step reproduction of the problem is helpful if there is no related issue -->
-
-<!--- Paste verbatim command output below, e.g. before and after your change -->
-
-```paste below
-
-```

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1 @@
+PULL_REQUEST_TEMPLATE/Unclear purpose or motivation.md

.github/PULL_REQUEST_TEMPLATE/Bug fix.md

@@ -0,0 +1,20 @@
+##### SUMMARY
+
+<!--- Describe the change below, including rationale and design decisions -->
+
+<!--- HINT: Include "Fixes #nnn" if you are fixing an existing issue -->
+
+##### ISSUE TYPE
+
+- Bugfix Pull Request
+
+##### ADDITIONAL INFORMATION
+
+<!--- Include additional information to help people understand the change here -->
+<!--- A step-by-step reproduction of the problem is helpful if there is no related issue -->
+
+<!--- Paste verbatim command output below, e.g. before and after your change -->
+
+```paste below
+
+```

.github/PULL_REQUEST_TEMPLATE/Documentation change.md

@@ -0,0 +1,19 @@
+##### SUMMARY
+
+<!--- Describe the change below, including rationale -->
+
+<!--- HINT: Include "Closes #nnn" if you are fixing an existing issue -->
+
+##### ISSUE TYPE
+
+- Docs Pull Request
+
+##### ADDITIONAL INFORMATION
+
+<!--- Include additional information to help people understand the change here -->
+
+<!--- Paste verbatim command output below, e.g. before and after your change -->
+
+```paste below
+
+```

.github/PULL_REQUEST_TEMPLATE/New feature.md

@@ -0,0 +1,19 @@
+##### SUMMARY
+
+<!--- Describe the change below, including rationale and design decisions -->
+
+<!--- HINT: Include "Resolves #nnn" if you are fixing an existing issue -->
+
+##### ISSUE TYPE
+
+- Feature Pull Request
+
+##### ADDITIONAL INFORMATION
+
+<!--- Include additional information to help people understand the change here -->
+
+<!--- Paste verbatim command output below, e.g. before and after your change -->
+
+```paste below
+
+```

.github/PULL_REQUEST_TEMPLATE/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1 @@
+Unclear purpose or motivation.md

.github/PULL_REQUEST_TEMPLATE/Tests.md

@@ -0,0 +1,20 @@
+##### SUMMARY
+
+<!--- Describe the change below, including rationale and design decisions -->
+
+<!--- HINT: Include "Closes #nnn" if you are fixing an existing issue -->
+
+##### ISSUE TYPE
+
+- Test Pull Request
+
+##### ADDITIONAL INFORMATION
+
+<!--- Include additional information to help people understand the change here -->
+<!--- A step-by-step reproduction of the problem is helpful if there is no related issue -->
+
+<!--- Paste verbatim command output below, e.g. before and after your change -->
+
+```paste below
+
+```

.github/PULL_REQUEST_TEMPLATE/Unclear purpose or motivation.md

@@ -0,0 +1,25 @@
+##### SUMMARY
+
+<!--- Describe the change below, including rationale and design decisions -->
+
+<!--- HINT: Include "Fixes #nnn" if you are fixing an existing issue -->
+
+##### ISSUE TYPE
+
+<!--- Pick one below and delete the rest -->
+
+- Bugfix Pull Request
+- Docs Pull Request
+- Feature Pull Request
+- Test Pull Request
+
+##### ADDITIONAL INFORMATION
+
+<!--- Include additional information to help people understand the change here -->
+<!--- A step-by-step reproduction of the problem is helpful if there is no related issue -->
+
+<!--- Paste verbatim command output below, e.g. before and after your change -->
+
+```paste below
+
+```