add ISSUE_TEMPLATE for github [ci skip] [circle skip]

.github/ISSUE_TEMPLATE

@@ -0,0 +1,41 @@
+<!-- Thanks for filing an issue! Before hitting the button, please answer these questions.-->
+
+**Is this a BUG REPORT or FEATURE REQUEST?** (choose one):
+
+<!--
+If this is a BUG REPORT, please:
+  - Fill in as much of the template below as you can.
+
+If this is a FEATURE REQUEST, please:
+  - Describe *in detail* the feature/behavior/change you'd like to see.
+
+In both cases, be ready for followup questions, and please respond in a timely
+manner. We might ask you to provide additional logs and data (tendermint & app)
+in a case of bug.
+-->
+
+**Tendermint version** (use `tendermint version` or `git rev-parse --verify HEAD` if installed from source):
+
+
+**ABCI app** (name for built-in, URL for self-written if it's publicly available):
+
+
+**Merkleeyes version** (use `git rev-parse --verify HEAD`, skip if you don't use it):
+
+
+**Environment**:
+- **OS** (e.g. from /etc/os-release):
+- **Install tools**:
+- **Others**:
+
+
+**What happened**:
+
+
+**What you expected to happen**:
+
+
+**How to reproduce it** (as minimally and precisely as possible):
+
+
+**Anything else do we need to know**: