doc(issue_template): refine

Author: idiotWu

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -45,4 +45,4 @@ body:
     attributes:
       label: Online Demo
       description: Provide a URL to an online demo that reproduces the bug. (Optional but recommended)
-      placeholder: "https://codesandbox.io/your-project"
+      placeholder: "https://codesandbox.io/s/your-project"

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -17,6 +17,6 @@ body:
   - type: textarea
     attributes:
       label: Proposal
-      description: How can you solve the problem?
+      description: How can we solve the problem?
     validations:
       required: true