added mode and storage engine

ISSUE_TEMPLATE.md

@@ -3,9 +3,17 @@ I'm using the latest ArangoDB of the respective release series:
 - [ ] 2.8
 - [ ] 3.0
 - [ ] 3.1
-- [ ] 3.2 Beta1
+- [ ] 3.2
 - [ ] self-compiled devel branch
 
+Mode:
+- [ ] Cluster
+- [ ] Single-Server
+
+Storage-Engine:
+- [ ] mmfiles
+- [ ] rocksdb
+
 On this operating system:
 - [ ] DCOS on
   - [ ] AWS
@@ -23,6 +31,7 @@ On this operating system:
 - [ ] Windows, version: 
 - [ ] MacOS, version:
 
+
 ### this is an AQL-related issue:
 [ ] I'm using graph features
 
@@ -41,7 +50,6 @@ Please provide a way to create the dataset to run the above query on; either by
 ### Foxx
 
 
-
 ### this is a web interface-related issue:
 I'm using the web interface with this browser:     running on this OS:
 - [ ] authentication is enabled?
@@ -61,4 +69,3 @@ Instead I would be expecting:
 
 ### this is an installation-related issue:
 Describe which steps you carried out, what you expected to happen and what actually happened.
-