fix: template (#69)

Author: sivchari

.github/ISSUE_TEMPLATE

@@ -1,5 +1,5 @@
 name: Go Conference 2023 Proposal
-description: Go Conference 2023のProposalです
+description: Go Conference 2023 Proposal
 title: "[Session title]: "
 assignees:
   - sivchari
@@ -9,23 +9,23 @@ body:
     id: speaker
     attributes:
       label: Speaker
-      placeholder: Gopher
+      placeholder: "Gopher"
     validations:
       required: true
 
   - type: textarea
     id: account
     attributes:
       label: SNS Accounts
-      placeholder: [Twitter](https://twitter.com/goconjp)
+      placeholder: "[Twitter](https://twitter.com/goconjp)"
     validations:
       required: false
 
   - type: textarea
     id: description
     attributes:
       label: Description
-      placeholder: What's new in Go1.20 ?
+      placeholder: "What's new in Go1.20 ?"
     validations:
       required: true
 
@@ -34,10 +34,10 @@ body:
     attributes:
       label: Session type
       options:
-        - LT(5min)
-        - Short Talk(20min)
-        - Challenge Session(20min)
-        - Long Talk(40min)
+        - LT (5min)
+        - Short Talk (20min)
+        - Challenge Session (20min)
+        - Long Talk (40min)
     validations:
       required: true