doc: add an issue template

It seems like I need to ask every single person to actually provide a
reproducible example, so let's try something new.

ISSUE_TEMPLATE.md

@@ -0,0 +1,37 @@
+Thank you for taking the time to file a bug report. The following describes
+some guidelines to creating a minimally useful ticket.
+
+Above all else: do not describe your problem, **SHOW** your problem.
+
+#### What version of the `csv` crate are you using?
+
+Replace this text with the version. (The version can be found in your
+Cargo.lock.)
+
+#### Briefly describe the question, bug or feature request.
+
+Replace this text with a description.
+
+#### Include a complete program demonstrating a problem.
+
+Whether you're asking for a feature, filing a bug or just asking a question,
+this section should almost always include some kind of code that you have
+written. The code provided should be able to be compiled by others and should
+be as feasibly small as possible.
+
+If you're reporting a bug, then the code should exhibit some undesirable
+characteristic.
+
+If you're asking a question, then the code should represent what you've tried
+so far.
+
+If you're requesting a feature, then provide code that does the closest
+possible thing to what you're requesting, if possible.
+
+#### What is the observed behavior of the code above?
+
+Replace this text with the output of the program.
+
+#### What is the expected or desired behavior of the code above?
+
+Replace this text with the expected or desired output of the program.