Fix the emoji's in the issue templates (#1308)

Author: daxian-dbw

.github/ISSUE_TEMPLATE/Bug_Report.md

@@ -1,6 +1,6 @@
 ---
-name: "Bug report :bug:"
-about: Report errors or unexpected behaviors
+name: "Bug report 🐛"
+about: Report errors or unexpected behaviors 🤔
 title: ''
 labels: ''
 assignees: ''

.github/ISSUE_TEMPLATE/Documentation_Issue.md

@@ -1,5 +1,5 @@
 ---
-name: "Documentation Issue :books:"
+name: "Documentation Issue 📚"
 about: Report issues in our documentation
 title: ''
 labels: Issue-Docs

.github/ISSUE_TEMPLATE/Feature_Request.md

@@ -1,5 +1,5 @@
 ---
-name: "Feature Request/Idea :rocket:"
+name: "Feature Request/Idea 🚀"
 about: Suggest a new feature or improvement (this does not mean you have to implement it)
 title: ''
 labels: Issue-Enhancement