Standardizing docs between python-slackclient and rtmbot

Added copyright to License File
Added standard format for issues/PRs
Added Code of Conduct
Moved doc/ to docs/

docs/example-plugins/counter.py

@@ -0,0 +1,13 @@
+from __future__ import unicode_literals
+# don't convert to ascii in py2.7 when creating string to return
+
+import time
+crontable = []
+outputs = []
+
+crontable.append([5, "say_time"])
+
+
+def say_time():
+    # NOTE: you must add a real channel ID for this to work
+    outputs.append(["D12345678", time.time()])