Separate the general issue template into community / core (#27469)

.github/ISSUE_TEMPLATE/0-community.md

@@ -1,8 +1,10 @@
 ---
-name: General Issue
+name: Community Issue
 about: Create a report describing a problem and a proposed solution
 title: ''
-assignees: ''
+labels: ["community"]
+assignees:
+  - @solana-labs/community-issue-subscribers
 ---
 
 #### Problem

.github/ISSUE_TEMPLATE/1-core-contributor.md

@@ -0,0 +1,15 @@
+---
+name: Core Contributor Issue
+about: Create a report describing a problem and a proposed solution
+title: ''
+assignees: ''
+---
+
+#### Problem
+<!--
+  This template should only be used by core contributors. If you
+  are not a core contributor, please use the "Community Issue" template
+  to ensure that your issue can be triaged appropriately.
+-->
+
+#### Proposed Solution