Update issue templates (#782)

* Update issue templates

Bounty Template

* Update bounty.md

* Update bounty.md

* Update bounty.md

.github/ISSUE_TEMPLATE/bounty.md

@@ -0,0 +1,28 @@
+---
+name: Bounty
+about: Bounty ticket for Harmony
+title: "[Bounty]"
+labels: help wanted
+assignees: ''
+
+---
+
+# About The Bounty
+https://github.com/harmony-one/harmony-open/blob/master/README.md
+
+# Category
+- [ ] bug
+- [ ] feature
+- [ ] document
+- [ ] dApp
+- [ ] test
+
+# Description
+
+# T-shirt Size
+<!-- XS, S, M, L, XL, XXL -->
+
+# Time Estimation
+
+# Explore All Bounties
+https://gitcoin.co/profile/harmony-one