Update ISSUE_TEMPLATE

.github/ISSUE_TEMPLATE

@@ -8,7 +8,7 @@
 
 ---
 ### Environment
-- [ ] React Native Navigation version: [FILL THIS OUT]
-- [ ] React Native version: [FILL THIS OUT]
-- [ ] Platform(s) (iOS, Android, or both?): [FILL THIS OUT]
-- [ ] Device info (Simulator/Device? OS version? Debug/Release?): [FILL THIS OUT]
+* React Native Navigation version: FILL THIS OUT
+* React Native version: FILL THIS OUT
+* Platform(s) (iOS, Android, or both?): FILL THIS OUT
+* Device info (Simulator/Device? OS version? Debug/Release?): FILL THIS OUT