CI: redirect feature requests to ideas in discussions (#16522)

Redirect feature requests to ideas in discussions

.github/DISCUSSION_TEMPLATE/ideas.yml

@@ -0,0 +1,29 @@
+labels: ["Idea"]
+body:
+  - type: checkboxes
+    id: checks
+    attributes:
+      label: Checked
+      description: Please confirm and check all the following options.
+      options:
+        - label: I searched existing ideas and did not find a similar one.
+          required: true
+        - label: I added a very descriptive title to this idea.
+          required: true
+  - type: textarea
+    id: feature-request
+    validations:
+      required: true
+    attributes:
+      label: Feature request
+      description: |
+        A clear and concise description of the feature proposal. Please provide links to any relevant GitHub repos, papers, or other resources if relevant.
+
+  - type: textarea
+    id: motivation
+    validations:
+      required: true
+    attributes:
+      label: Motivation
+      description: |
+        Please outline the motivation for the proposal. Is your feature request related to a problem? e.g., I'm always frustrated when [...]. If this is related to another GitHub issue, please link here too.

.github/ISSUE_TEMPLATE/config.yml

@@ -7,6 +7,9 @@ contact_links:
   - name: Discord
     url: https://discord.gg/6adMQxSpJS
     about: General community discussions
+  - name: Feature Request
+    url: https://www.github.com/langchain-ai/langchain/discussions/categories/ideas
+    about: Suggest a feature or an idea
   - name: Show and tell
     about: Show what you built with LangChain
     url: https://www.github.com/langchain-ai/langchain/discussions/categories/show-and-tell