Update issue templates

Author: liydu

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,6 +1,6 @@
 ---
 name: Bug report
-about: Create a report to help us improve Azure RTOS
+about: Create a report to help us improve Azure RTOS.
 title: ''
 labels: bug
 assignees: ''

.github/ISSUE_TEMPLATE/hardware-or-architecture-support.md

@@ -2,7 +2,7 @@
 name: Hardware or architecture support
 about: Suggest adding hardware or new architecture support.
 title: ''
-labels: enhancement
+labels: ''
 assignees: ''
 
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